Visit的过去式

读作：为则特德

"visited"是visit的过去式和过去分词形式，意思是“访问”、“参观”、“拜访”等。这个词在日常生活中经常被使用，下面将从以下几个方面进行阐述visited的意思。一、访问"visited"最常见的意思是“访问”，指的是去某个地方或某个人的家中进行拜访或会面。例如：I visited my friend in the hospital yesterday.（昨天我去医院看望了我的朋友。）二、参观"visited"还可以表示“参观”，指的是去某个地方或某个景点进行观光或游览。例如：We visited the Great Wall last year.（去年我们参观了长城。）三、拜访"visited"还可以表示“拜访”，指的是去拜访某个人或某个机构。例如：I visited my professor during his office hours.（我在教授的办公时间去拜访了他。）四、检查"visited"还可以表示“检查”，指的是去某个地方或某个机构进行检查或审查。例如：The health inspector visited the restaurant to check the hygiene.（卫生检查员去餐厅检查卫生情况。）五、探望"visited"还可以表示“探望”，指的是去看望某个人，通常是因为他们生病或遇到了困难。例如：I visited my neighbor to offer my condolences after her husband passed away.（邻居的丈夫去世后，我去探望她并表示慰问。）总之，"visited"是一个常用的英语单词，意思是“访问”、“参观”、“拜访”等。在日常生活中，我们可以根据具体的语境来理解它的含义。

凡具有下列条件之者，可申请英国探亲签证：夫妻一方或父母或兄弟姐妹（包括养父母、养兄弟姐妹）在英国，且取得英国国籍的；祖父母或养祖父母在英国，且取得英国国籍的；子女（包括养子女）及孙子女（包括养孙子女）在英国定居，且取得英国国籍的；叔伯或堂兄弟在英国定居，且取得英国国籍的；姑、姨及表兄弟姐妹在英国定居，且取得英国国籍的；有直系亲属在英国工作或学习的。 ---陪读签证在英国，父母不可以陪读，但是配偶或者未成年子女可以陪读，在父母学业完成之时随父母一同回国。男女朋友或未婚夫、妻则不被承认。 如果夫妻间有一方在英国学习期间，学生配偶(陪读身份) 可以申请团聚签证。英国规定配偶可读书或工作，不需要工作许可，所获签证将和已在英国一方一样长。办理英国陪读签证，申请人除了具备两个基本条件，一是合法婚姻，一是有足够的经济保障之外，还需要认真准备材料。

["vizitid]动词过去式和过去分词的读法:当动词的最后一个字母是清辅音时 ed读[t]当动词的最后一个字母是浊辅音时 ed读[d]当动词的最后一个字母是以t或d结尾的 ed读[id]过去式很多人都读不准确。。其实不难，只要每次读的时候看看原单词的最后一个你就知道啦。。

这个需要看使用的情况，不同情况下功能不同

visited，动词过去式分为两种：一种是规律的，有规律的分为四中①去e＋ed②铺＋y的去y改i＋ed③双写＋ed④和＋ed。一种是没规律的，不规则的只有自己背了。

1、visited英[u02c8vu026azu026atu026ad]美[u02c8vu026azu026atu026ad]，v.访问; 拜访; 看望; 参观; 访问(互联网上的网站); (短暂地)作客，逗留;visit的过去分词和过去式。 2、[例句]Its my first visit to New York.这是我第一次访问纽约。

visited 是动词， 通常不可用为形容词（例外见下）另外， visiting 和 visitable 也是形容词。例：The Summer Palace is one of the most visited tourist sites in China.John is a visiting professor at Tsinghua.We need to make schools more accessible and visitable.你的句子 that 要改为 the one ：This museum is the one you visited the other day.

visit通常用作及物动词，后面跟上名词或者代词作宾语。例如：一、visit的含义二、visit的用法I visited my friend in the hospital yesterday.（我昨天去医院看望了我的朋友。）1. 拜访

visited英 [ˈvɪzɪtɪd] 美 [ˈvɪzɪtɪd] v.访问;拜访;看望;参观;访问

"visited" 和 "came" 的区别在于它们的意义和用法不同。"Visited" 表示"参观"，"拜访"，"访问"等意思，通常用于描述去某个地方看望某人或者参观某个地方。例如：Yesterday, I visited my friend in the hospital.（昨天我去医院看望了我的朋友。）"Came" 表示"来"，通常用于描述自己到达某个地点。例如：She came to the party late.（她来参加聚会的时候已经很晚了。）

visit 英["vu026azu026at]美[u02c8vu026azu026at]vt.& vi. 访问;探望;参观;游览vi. 作客n. 访问，参观;逗留[例句]Schoolchildren often visit the place.学生们经常参观这里。1. You can visit the whole palace except for the private apartments. 整座宫殿除内殿外均可参观。来自《权威词典》2. The visit was conducted with all due ceremonial. 访问按照一切应有的礼仪进行。来自《权威词典》3. his first-ever visit to London 他对伦敦的初次访问来自《权威词典》4. I have been fortunate enough to visit many parts of the world as a lecturer. 我很有福气，去过世界许多地方作演讲。

visit D.J.[u02c8vizit] K.K.[u02c8vu026azu026at] vt. & vi. 访问; 探望; 参观; 游览 They are visiting in that city. 他们正在那个城市参观访问。 I"m just going to visit my friend Smith. 我正要去拜访我的朋友史密斯。 The schools are regularly visited by officials from the Ministry of Education. 教育部的官员们定期视察各学校。 在…逗留; 住宿 He is visiting at a hotel nearby. 他暂住在附近的一家旅馆里。 Many migratory birds visit this lake annually. 许多候鸟每年到这个湖上作短期逗留。 侵袭 vi. 聊天; 闲谈 Let"s sit here and visit together for a while. 让我们坐在这里谈一会儿。 n. 访问; 参观, 游览; 逗留 During our visit to London we often went to the theatre. 我们在伦敦逗留时常去看戏。 聊天, 谈话 We had a nice visit on the phone. 我们在电话里谈得很高兴。

visit的各种时态　　过去式: visited　　过去分词: visited　　现在分词: visiting　　visit的用法　　visit的用法1：visit用作名词的意思是“来或去见某人或到某处访问”“参观”“游览”“逗留”。在口语中还可指“聊天,谈话”。　　visit的用法2：visit的基本意思是“访问某人或某地”,即“访问”“探望”“参观”“视察”“逗留”“出诊”,指因为礼节、友谊、生意或职责的需要而来到某人处并短时间地与其呆在一起,也可指较长时间地以客人身份在某人家里或所去休息、娱乐、观光的地方居住。引申为“(疾病、灾害等)侵袭”“降临”“惩罚”“施加报复或报应”。　　visit的用法3：visit既可用作不及物动词,也可用作及物动词。用作及物动词时,接名词、代词作宾语。可用于被动结构。

　　visited的读音是["vu026azu026atu026ad]。visited是visit的过去分词和过去式，意思是：参观、访问、拜访、看望。用visited造句如下：“I visited with him in San Francisco.” 　　visit的用例 　　1、Helen had recently paid him a visit.海伦最近去探望了他。 　　2、He"ll be visiting four cities including Cagliari in Sardinia.他将要访问4个城市，包括萨迪尼亚的卡利亚里。 　　3、I paid a visit to my local print shop.我去了我们当地的照片冲洗店。 　　4、If necessary the patient can then visit his doctor for further advice.如有必要，病人可以上门咨询自己的医生以得到更多的建议。 　　5、Violence is visited upon us every day.暴力事件每天都会降临在我们身上。

拜访了我的叔叔

visit英文读音为：英 [u02c8vu026azu026at]，美 [u02c8vu026azu026at]。词典释义：v. 访问；拜访；使某人遭受；参观；探望；视察；检查；巡视；闲聊；游览n. 参观；访问；拜访；游览；作客；视察；闲聊；逗留；非正式谈话牛津字典解释：一、作动词时1、go to see and spend time with（someone）socially访问，拜访例句：I came to visit my grandmother. 我来看祖母。2、（常作be visited）inflict（something harmful or unpleasant）on someone使某人遭受（有害或不快之事）例句：The mockery visited upon him by his schoolmates. 他的同学对他的嘲讽。二、做名词时an act of going or coming to see a person or place socially，as a tourist，or for some other purpose 参观；访问；拜访；游览；作客；视察例子：a visit to the doctor. 看病。

visited是动词visit的过去式和过去分词。造句如下： We visited the Great Wall yesterday. 昨天我们参观了长城。 I visited my parents last month. 上个月我看望了父母。

visited 不同，过去式是规则变化got went did 是不规则变化

它们的区别是主动与被动语态。be visited:被访问。visited：访问，它是visit的过去式和过去分词形式。visit:拜访，访问.。

现在分词：visiting。visit，作名词时译为“访问，参观；浏览；逗留；咨询；会面，闲聊”，作动词时译为“访问，参观；浏览；视察；逗留；咨询；闲谈；救助；遭受”。visit基本含义v.访问; 拜访; 看望; 参观; 访问(互联网上的网站); (短暂地)作客，逗留;n.访问; 参观; 游览; 逗留; 看望; (到网站的)访问; 碰头; 会面;[例句]If you have time, pay a visit to the local museum.你若有空，参观一下当地的博物馆。第三人称单数：visits现在分词：visiting过去式：visited过去分词：visitedvisit双语例句I timed our visit for March 7. 我把我们访问时间定在3月7日。I went back to visit my old school. 我回去拜访了母校。Helen had recently paid him a visit. 海伦最近拜访了他。

visitvt.&vi.访问;探望;参观;游览;vi.作客;n.访问，参观;逗留;vt.拜访，参观;[英][u02c8vu026azu026at][美][u02c8vu026azu026at]第三人称单数：visits过去分词：visited现在进行时：visiting过去式：visited

因为要双写再加ed必须同时满足。一个元音字母＋一个辅音字母结尾。例如：stop（只有一个音节，通常看做节）--stopped总之重读闭音节就要双写，什么是重读闭音节即两个辅音中间夹一个元。visit不是重读闭音节，它的的重读在前面的vi，所以不用双写t加ed。

visited，读成拼音vi-zi-tid。

visited,saw,did这3个动词中不属于同类的一项是：visited。解析：visited的原形是visit,saw的原形是see,did的原形是do。这3个动词中，只有visit的过去式是规则变化，其余3个是动词的不规则变化形式。

visit过去式为visited，visit用作名词的意思是“来或去见某人或到某处访问”“参观”“游览”“逗留”。在口语中还可指“聊天,谈话”。 visit的过去式例句 1. Her daughters visited him from time to time when he was ill. 他生病的时候她的女儿们时常去探望他。 2. In most of the residence halls we visited, rules prohibit disorderly conduct. 在我们走访的学生宿舍里，大多明令禁止胡作非为。 3. Death and suffering had been visited on thousands of innocents. 死亡和苦难降临在了数千名无辜的人身上。 4. Visited Park West. Viewed a flat, no. 76. Which I like. 去了中央公园西路，看了一套公寓，76号，我很喜欢。 5. Mr Dinkins visited the bereaved family to offer comfort. 丁金斯先生前往死者家吊唁。 6. Pope John Paul received a rapturous reception when he visited East Timor. 在访问东帝汶期间，教皇约翰·保罗受到了热烈的欢迎。 7. They have been visited by creatures from outer space. 有外星人拜访了他们。 8. He visited the Institute of Neurology in Havana where they both worked. 他访问了两人都曾工作过的哈瓦那的神经病学研究所. 9. His officials have visited Washington to press their case for economic aid. 他的官员们已经访问了华盛顿，竭力要求得到经济援助。 10. He visited Thailand and Singapore to tout for investment. 他访问了泰国与新加坡，以期招揽投资。

visit。根据搜狐网查询得知，visited是visit的过去式，所以visited的原形是visit。visited：拜访；看望；参观；访问(互联网上的网站)；(短暂地)作客，逗留。

　　1、visit的过去分词是visited。 　　2、visit：访问; 拜访; 看望; 参观; 访问(互联网上的网站); (短暂地)作客，逗留; 　　3、[例句]：He wanted to visit his brother in Worcester.他想去看望住在伍斯特的哥哥。

visited

直接加ed，visited

拜访

有时一起用。He visited his grandparents in the morning.He visited his grandparentslast weekend.

visit的过去式是直接在后面加ed

vt.& vi.访问；探望；参观；游览 vi.作客 n.访问,参观；逗留 vt.拜访,参观 第三人称单数：visits 过去式：visited 过去分词：visited 现在分词：visiting 易混淆的单词：VISIT Visit 很高兴为您解答,【语数英科】团队为您答题. 请点击下面的【选为满意回答】按钮, 如果有其他需要帮助的题目,您可以求助我. 你可以随时加入我团队,我随时恭候.

亲,因为before和现在完成时连用.不用告诉我你是给别人家教,你自己不知道?,4,首先，句意是在此之前我已经去过了，自然是现在完成时。其次，如果你用visited，就是过去时态，后面却是现在时态it is这不行的，时态要一致,2,visited表明你去了广州了，不强调与现在的关系。have visited是说你去过了，并对现在的产生了作用。此题的情景关键在于，你去过，不想再去了，所以要选取对现在产生影响的选项。,0,英语单选初三.求详解我觉得在这里visited和have visited没什么区别啊. -- Would you like to visit Guangzhou with me this summer vacation? -- No． I ________ it before． Besides,it"s hot and humid in summer． A．visit B．visited C．will visit D．have visited 为什么不能用visited而要用have visited?

你直接倒装过去，原句是thefirstplacethatwevisitedwas***，倒装成wevisitedtheplace,如果visit后面可以直接接that前面的名词，那么就用which，如果不能，就用where,比如，thisistheplacewhereIgrewup,倒装过来是Igrewuptheplace,肯定不行，grewup后面怎么能接地点呢，所有用where，thisistheplacewhereIgrewup可以改成用which的，thisistheplacewhichIgrewupat，就对了，倒装过来是Igrewupattheplace，是对的，所以可以用which。

visit的名词形式是visitor visit v.访问;拜访;看望;参观;访问(互联网上的网站);(短暂地)作客，逗留 n.访问;参观;游览;逗留;看望;(到网站的)访问;碰头;会面 第三人称单数： visits 现在分词： visiting 过去式： visited 过去分词： visited 扩展资料 　　He gave us a very sketchy account of his visit. 　　他跟我们非常粗略地讲了他参观的情况。 　　Is this a social visit, or is it business? 　　这是社交性的"拜访，还是业务性的？ 　　It"s my first visit to New York. 　　这是我第一次访问纽约。

以/t/或/d/结尾的词后面加-ed构成过去式时，ed发/id/的音, 如：needed/visited。以元音结尾的词后面加-ed时，ed发/d/。如：played.

visit vt.& vi.访问；探望；参观；游览 vi.作客 n.访问,参观；逗留 vt.拜访,参观 visiting 是动名词 visit在这里作名词,所以填visit

n.帐篷;帐棚 vt.住帐蓬用帐蓬遮盖;向…供应帐篷;将塞条嵌进（伤口）;观察;看护;照料第三人称单数： tents复数： tents现在分词： tenting过去式： tented过去分词： tented短语搭配crib tent 有帐婴儿床tent introducer 塞条导引器Tent Card 座台餐牌 ; 立卡 ; 展示卡party tent 宴会帐篷 ; 派对篷房 ; 聚会帐篷relief tent 救灾帐篷pet tent 宠物帐篷 ; 宠物帐 ; 宠物篷kids tent 儿童帐篷fishing tent 钓鱼帐篷

红警都可以，但是要以兼容模式运行！实况足球，跑跑卡丁车，…

Whether in the workplace, or in sports, or amongst members of a community, effective teamwork can produce extraordinary results. However, that is easier said than done, effective teamwork does not happen automatically. First, let us see the conditions that help develop and maintain effective teamwork: common group objectives and goals understood and committed to by all team members; efforts to develop and use the unique skills and abilities of each team member in a way that helps a team meet its objectives; efforts to develop in team members flexibility, creativity and sensitivity to the needs of others; a clear value reinforced by our management team, on trust, openness of communication among team members and between team members; efforts to increase each member"s sense of belonging to the team; time and attention devoted to teamwork; and rapid and accurate feedback to team members about the effectiveness of their actions and decisions. Now, let us see the conditions that present challenges to effective teamwork: team members are new or change often; persons on the team are unsure of or not happy with their roles; time pressures make it difficult to adequately develop project and team; the locations or workload of team members make it difficult for team members to have regular contact with each other; there is uncertainty about the goals or tasks to be accomplished, or individual team members are unsure of their task proficiency; differences in perceptions exist among team members and team roles; communication breakdown exists (this goes for managers also); there are taboo topics that affect team"s performance; and participation is not uniformly spread among team members, or there is not adequate punishment for those that do not do their part. In addition to the basic requirements for team members who should be open and honest with one"s ideas, concerns and values and have the ability to commit to a shared goal, to listen and respond to others in an objective and productive way, to take on different roles in the group in order to accomplish shared ends, and to be a leader as well as a follower, there are a number of factors required to cohere together, working seamlessly, for an effective team to develop and work. Good leadership, the right balance of the right people, effective communication, defining clear-cut roles, creating procedures for conflict resolution and setting a good example are some of the factors vital for building a good team that works successfully. One of the most important aspects of effective teamwork is effective leadership. This means that the team leader should have the skills to create and maintain a working culture that is positive. This helps to motivate and even inspire the team members to get involved in creating an environment where there is a positive approach to work, along with high levels of commitment. A good team leader is a person who not only focuses himself/herself on the purpose and direction of the team, but also makes sure that the other members of the team share this focus. A good team leader also has to be able to promote a high level of morale amongst the team members so that they feel supported and valued. This is particularly useful for preventing the bane of most office cultures – that of backbiting, rumormongering, gossip mongering and cronyism – which can derail the efforts of any teamwork. The balance of a team involves having people whose experience, skills, perspectives, interests and contributions complement one another, rather than duplicate or counteract each other. For example, it is no good having a team full of creative people who have lots of new ideas, but do not have the people who have the stamina and stickability to see those ideas through to completion. Similarly, a team that is full of people who are steady, strong workers but have little spark or creativity, will also be impoverished by comparison with a balanced team. If it is not to become stale and sterile, a team needs people who are prepared to risk conflict by challenging existing norms and assumptions, but, by the same token, a team also needs its peacemakers. Differences between team members can, in themselves, lead to conflict but the diversity of the team and the balance that this can achieve, will generally more than make up for any such conflicts. It goes without saying that communication is a vital factor of interpersonal interaction, and the very term "teamwork" represents interpersonal interaction. Hence, one of the key aspects of effective teamwork is open communication, wherein it enables the members of the team to articulate their feelings, express their plans, share their ideas, and understand each other"s viewpoints. Grappling and sorting out the complexities involved in communication is thus one of the challenges of developing and sustaining effective teamwork. It is necessary for teams to know clearly what their purpose is, what role each member of the team has to play, what each person is responsible for, what is not within their scope, and the resources they have to achieve their goals. The team leader can enable this by defining the purpose in a clear-cut manner up front. The team, on their part, can help by building processes wherein the roles and scope of each member as well as the team are kept in focus, and avoiding anything that undermines effective teamwork. No matter how good a team may be, conflicts will inevitably occur some time or the other. The best way to counter this is to have structured methods of resolving them. Team members should have a way of expressing their opinions without fear of causing offense to anyone. Direct confrontation can also be allowed in a moderated manner, so that matters that may have been simmering can be aired out and cleared. Instead of ignoring and procrastinating these issues, a hands-on approach that resolves them quickly is better. In fact, it is advisable for the team leader to actually sit with the parties in conflict and work out the differences between them, without taking sides and making sure to remain objective. Eventually, the conflicts can actually be used as a chance to reveal underlying problems that may be in existence within the team. And finally, effective teamwork can only come about when the team leader sets a good example, which can be emulated by the team members. In order to keep the team committed, positive and motivated, the team leader himself/herself has to have all these qualities and make it apparent that he/she does. After all, the team leader is the person the team looks to for support, direction and guidance, hence, any cynicism or negativity on his/her part is picked up by the team and is reflected in their teamwork. So, even if it means forcing yourself to, it is important to maintain a supportive and positive attitude always.你不会自己编辑一下？适当做一下删减？

到360软件管家里面下载一个Adobe Flash Player for IE 安装就可以了。

《beautiful ones 》 ,suede乐队

嗯。装win7（32），不要以为数字越大越好

小李子的全英文介绍：Thank you all so very much. Thank you to the Academy, thank you to all of you in this room. I have to congratulate the other incredible nominees this year. "The Revenant" was the product of the tireless efforts of an unbelievable cast and crew. First off, to my brother in this endeavor, Mr. Tom Hardy. Tom, your talent on screen can only be surpassed by your friendship off screen… thank you for creating a transcendent cinematic experience. Thank you to everybody at Fox and New Regency…my entire team. I have to thank everyone from the very onset of my career… To my parents, none of this would be possible without you. And to my friends, I love you dearly, you know who you are.And lastly I just want to say this: Making ‘The Revenant" was about man"s relationship to the natural world. A world that we collectively felt in 2015 as the hottest year in recorded history. Our production needed to move to the southern tip of this planet just to be able to find snow. Climate change is real, it is happening right now. It is the most urgent threat facing our entire species, and we need to work collectively together and stop procrastinating. We need to support leaders around the world who do not speak for the big polluters, but who speak for all of humanity, for the indigenous people of the world, for the billions and billions of underprivileged people out there who would be most affected by this. For our children"s children, and for those people out there whose voices have been drowned out by the politics of greed. I thank you all for this amazing award tonight. Let us not take this planet for granted. I do not take tonight for granted. Thank you so very much.

你是说他们mv中出现的那个滑板车吗？是wheelman，但是中国没有哦

拖沓的词语解释是：拖沓tuōtà。(1)形容做事拖拉。拖沓的词语解释是：拖沓tuōtà。(1)形容做事拖拉。词性是：形容词。结构是：拖(左右结构)沓(上下结构)。注音是：ㄊㄨㄛㄊㄚ_。拼音是：tuōtà。拖沓的具体解释是什么呢，我们通过以下几个方面为您介绍：一、引证解释【点此查看计划详细内容】⒈不爽利；不简洁。引元无名氏《黄花峪》第一折：“见一座摧塌了山神古庙堂，我这里思也波量。端的着谁上香，你看那拖拖沓沓乔供养。”明沉德符《野获编·词曲·邱文庄填词》：“邱文庄淹博，本朝鲜_，而行文拖沓，不为后学所式。”清朱彝尊《＜梦粱录＞跋》：“岁辛巳，寓居昭庆僧楼，取而卒读之，嫌其用笔拖沓，不知所裁。”秦牧《艺海拾贝·辩证规律在艺术创造上的运用》：“如果在应该简略的地方不加简略，力量平均使用，繁冗拖沓，那种感人的力量也一定会大打折扣。”⒉连绵不断貌。引明李东阳《尼山春晓图》诗：“__尼山云，忽忽天向晓，依微远峰露，拖沓层城绕。”二、国语词典做事拖泥带水，不干脆。词语翻译英语dilatory,procrastinating,obstructive德语langsam法语Procrastination三、网络解释拖沓拖沓是一个汉语词汇，拼音是tuōtà，意思是阻碍和有意拖沓的战术，形容做事拖拉、阻碍和有意拖沓的；不爽利；不简洁；连绵不断。关于拖沓的近义词拖拉疲塌含糊关于拖沓的反义词俐落爽利利落关于拖沓的诗词《文风·长文拖沓水无油》关于拖沓的诗句你就说我拖沓你就说我拖沓长文拖沓水无油关于拖沓的成语麇至沓来拖拖沓沓纷至沓来沓冈复岭泄泄沓沓沓来_至拖拖拉拉沓来踵至重规沓矩改口沓舌关于拖沓的词语拖后腿沓来_至沓冈复岭拖油瓶繁冗拖沓改口沓舌重规沓矩沓来踵至杂沓而至纷纭杂沓关于拖沓的造句1、就像是做了一场无比拖沓无比冗长的梦，身心俱疲，皮肉下的每个关节都在痛，可是却清楚的知道，我的世界里再也没有你。2、由于不是很高，不包太长的裙子，促膝或略高于，长时间看拖沓，沉重。面料不要太厚，太厚看起来很平淡，太薄而不能成为类型，而不是谦虚。3、无论是工作还是学习，都要有只争朝夕的精神，懒惰和拖沓是要不得的。4、你这篇文章拖沓冗长，废话连篇，没有突出主题思想。5、从听众的视觉线索可以看出演讲很拖沓。演讲者在详细讲某特点上用时过长，或者某点需要更多的解释。点此查看更多关于拖沓的详细信息

smooth operator

选中一个via,右键选find similar object.然后在pcb inspector 中勾上solder mask tenting-top 和solder mask tenting-bottom就行了.或者还有个变通的方法,在altium示例pcb上看到的,在solder mask expansion规则里新建一个针对via的规则,并把expansion设置成一个比较小的负数.这样放置的via都是被mask层覆盖的.在altium的3D模式下可以看出区别(来源：www.pcbwork.net)