we must ask Tom to clean his room 改称被动语态

一、如何变人称：
下面有一句顺口溜“一随主.二随宾,第三人称不更新”.“一随主”是指在直接引语变间接引语时,如果从句中的主语是第一人称或被第一人称所修饰.从句中的人称要按照主句中主语的人称变化如：
She said. "My brother wants to go with me. "→She said her brother wanted to go with her.
“二随宾”是指直接引语变间接引语时,若从句中的主语及宾语是第二人称.或被第二人你所修饰.从句中的人称要跟引号外的主句的宾语一致.如果引号外的主句没有宾语.也可以用第一人称,如：
He said to Kate. "How is your sister now?"→He asked Kate how her sister was then.
“第三人称不更新”是指直接引语变间接引语时.如果从句中的主语及宾语是第三人称或被第三人称所修饰从句中的人称一般不需要变化如：
Mr Smith said. "Jack is a good worker."→Mr Smith said Jack was a good worker.
二、如何变时态：
直接引语在改为间接引语时、时态需要做相应的调整.
现在时它需改为过去时态；过去时态改为完成时；过去完成时则保留原来的时态.如：
1)She said. "I have lost a pen."→She said she had lost a pen
2)She said. "We hope so."→She said they hoped so.
3) She said. "He will go to see his friend."→She said he would go to see his friend.
但要注意在以下几种情况下.在直接引语变为间接引语时,时态一般不变化.
①直接引语是客观真理.
"The earth moves around the sun and the moon moves around the earth, the teacher told me. → The teacher told me the earth moves around the sun and the moon moves around the earth.
②直接引语是过去进行时,时态不变.如：
Jack said. "John, where were you going when I met you in the street?"→Jack asked John where he was going when he met him in the street.
③直接引语中有具体的过去某年、某月、某日作状语,变为间接引语时,时态不变.如：
Xiao Wang said. "I was born on April 2l, 1980." →Xiao Wang said he was born on April 20, 1980.
④直接引语如果是一般现在时.表示一种反复出现或习惯性的动作,变间接引语,时态不变.如：
He said, "I get up at six every morning." →He said he gets up at six every morning.
⑤如果直接引语中的情态动词没有过去时的形式（例：ought to, had better, used to)和已经是过去时的形式时,（例：could, should, would, might）不再变.如：
Peter said. "You had better come have today." →Peter said I had better go there that day.
三、如何变状语：
直接引语变间接引语,状语变化有其内在规津,时间状语由“现在”改为“原来”（例：now变为then, yesterday.变为 the day before）地点状语,尤其表示方向性的,或用指示代词修饰的状语,由“此”改为“彼”（例：this 改为that),如：
He said, "These books are mine." →He said those books were his.
四、如何变句型：
①直接引语如果是陈述句,间接引语应改为由that引导的宾语从句.如：She said, "Our bus will arrive in five minutes."→She said that their bus would arrive in five minutes.
②直接引语如果是反意疑问句,选择疑问句或一般疑问句,间接引语应改为由whether或if引导的宾语从句.如：He said, "Can you swim, John?" →He asked John if he could swim.
"You have finished the homework, haven‘t you?" my mother asked. →My mother asked me whether I had finished the homework.
"Do you go to school by bus or by bike?" →He asked me if I went to school by bus or by bike.
③直接引语如果是特殊问句,间接引语应该改为由疑问代词或疑问副词引导的宾语从句（宾语从句必须用陈述句语序）.
She asked me, "When do they have their dinner?"→ She asked me when they had their dinner.
④直接引语如果是祈使句,间接引语应改为"tell(ask, order, beg等) sb (not) to do sth."句型.如：
"Don’t make any noise," she said to the children. →She told (ordered) the children not to make any noise. "Bring me a cup of tea, please," said she.→She asked him to bring her a cup of tea.
⑤直接引语如果是以“Let‘s”开头的祈使句,变为间接引语时,通常用“suggest +动句词（或从句）.”如：
He said, "Let’s go to the film." →He suggested going to the film.或He suggested that they should go to see the film.
引述别人的话有两种方式：一是使用引号引出人家的原话,这叫做直接引语；一是用自己的话把人家的话转述出来,这叫做间接引语.例如：
John said, "I’m going to London with my father."
约翰说："我要和父亲到伦敦去."（引号内是直接引语）
John said that he was going to London with his father.
约翰说,他要和他父亲去伦敦.（宾语从句是间接引语）
由直接引语变为间接引语,分以下情况：
1． 直接引语是陈述句时
间接引语为that引导的宾语从句（口语中that可以省略）,主句的引述动词主要有say ,tell, repeat, explain, think等.
He said , "You are younger than I."-’He said (that ) I was younger than him.
2.直接引语是疑问句时
间接引语为陈述语序：主句的谓语动词say 改为ask,或改为wonder, do not know, want to know, be not sure, be puzzled等.
（1） 一般疑问句或反意疑问句变为if (whether)引导的宾语从句.
She said, "Do you often come here to read newspapers?"
→She asked me if (或whether)I often went there to read newspapers.
She asked me , "You have seen the film, haven’t you?"
→She asked me whether(或if )I had seen the film.
（2） 选择疑问句变为whether….or 宾语从句.
I asked him, "Will you stay at home or go to a film tonight?"
→I asked him whether he would stay at home or go to a film that night.
(3)特殊疑问句变为由原来的疑问词引导的宾语从句.
He asked , "Where do you live?"
→He asked me where I lived.
3.直接引语是祈使句时
间接引语为不定式,作ask , tell, beg, order, warn, advise等动词的宾语补足语（don’t 变为not ）.
The teacher said to the boy, "Open the window."→The teacher told the boy to open the window.
His father said to him , "Don’t leave the door open."→His father told him not to leave the door open.
[注意]
（1） 有些表示建议、提议、劝告或要求的祈使句,可以用suggest ,insist等动词 加以转述.例如：
He said, "Let’s go to the theatre."
→He suggested (our )going to the theatre.或He suggested that we(should) go to the theatre.
(2) "Would you mind opening the window?" he asked.
→He asked me to open the window.
"Why don’t you take a walk after supper?" he asked .
→he advised me to take a walk after supper.
"Shall we listen to the music?" he asked.
→He suggested listening to the music.
4.直接引语是感叹句时
间接引语为what 或how 引导,也可以用that 引导.
She said, "What a lovely day it is !"
→She said what a lovely day it was .或She said that it was a lovely day.
5．如果主句谓语动词为各种现在时或一般将来时,则间接引语中的动词仍保持直接引语原来时态.如果主句谓语动词为过去时,间接引语中的动词时态按下列变化：
（1） 一般现在时变为一般过去时
（2） 现在进行时变为过去进行时
（3） 一般将来时变为过去将来时
（4） 现在完成时变为过去完成时
（5） 一般过去时变为过去完成时
（6） 过去完成时不变,仍为过去完成时
[注意]
（1） 如果直接引语是表示客观真理时,变为间接引语,一般现在时不改为一般过去时.如：
The teacher said "The earth goes round the sun."
→The teacher said that the earth goes round the sun.
（2） 如果直接引语中有明确表示过时间的状语,变为间接引语时,一般过去时不改为过去完成时.如：
He said to me, "I was born in 1973."
→He told me that he was born in 1973.
(3)如果直接引语所述事实在当时和目前同样生效,变为间接宾语时,一般现在时不改为一般过去时.如：
He said, "I’m a boy, not a girl."
→He said that he is a boy ,not a girl.
(4)如果直接引语中的谓语动词表示一种反复出现或习惯动作,在变为间接引时,一般现在时不改为一般过去时.如：
The girl said, "I get up at six every morning."
→The girl said that she gets up at six every morning.
(5)如果直接引语中含有since, when, while 引导的表示过去时间的状语从句,在变为间接引语时,只改变主句中的谓语动词,从句的一般过去时则不变.如：
He said to me, "I have taught English since he came here ."
→He told me that he had taught English since he came here.
(6)如果直接引语中含有情态动词 must, need, had better以及情态动词的过去式could, might, should, would,在变为间接引语时,这些情态动词没有时态的改变.例如：
The teacher said to me . "You must pay more attention to your pronunciation."
→The teacher told me that I must (have to ) pay more attention to my pronunciation.
He said , "I could swim when I was only six ."
→He said that he could swim when he was only six.
6.代词等一般地应作用相应的变化.
指示代词 this ---that
these--- those
表示时间的词 now --- then
today--- that day
this week(month ,etc) ----that week (month ,etc)
yesterday ----the day before
last week(month) --- the week(month) before
three days(a year)ago---three days(a year)before
tomorrow ----the next (following ) day
next week(month)--the next(following)week(month)
表地点的词 here --there
动词 bring -- take
come --go
2, My employer said that I needn't come in the next day,and I could take a day off.

同志别太懒.我也不是十分擅长阅读.我是这样想的.到底对错也不知道.给点悬赏分啊.
1.“好事”指用筷子吃饭方便进食还可以灵活手指、锻练脑力,有益身心健康,“一举”是一件事情文中指用筷子,“多得”在学者眼里指锻练脑力,在武士眼里指可以灵活手指.
2.第三段：用筷子吃饭,得心应手,灵活自如,十分方便.
第四段：我们中国的筷子 各式各样 原料也各异 最为出名的有驰名中外
（就是每一段的开头第一句的总起句）
3.筷子的来源、好处

1.爸爸想了想,笑笑说,也许,我的想法再美些.
2.老师对我说,萍萍身体不好,我要多关心她.
　直述句改为转述句,冒号要改为逗号,双引号要去掉,再加上句号.转述句改直述句,要加上冒号和引号,再加上句号.
角度换成了说明后,人称也会变化.
1.引述是直接引用别人的话,而转述则是转达别人说的话, 因此,引述句改为转述句时,说话人即第一人称“ 我 ”要改 为第三人称“ 他 ” 或“ 她 ”.
如：张童说：“我一定要坚持长跑锻炼. ” 　　
改：张童说,他一定要坚持长跑锻炼. 　　
2.当引述内容涉及其他人称时的改法 . 　　
如：姐姐说：“ 你说得对,我就这样做.” 　　
改：姐姐说,我说得对,她就这样做 . 　　
上面的例句中涉及了第二人称,在改为转述句时就应改为 第一人称.还应注意,冒号和引号前的内容不变. 　　
3.引述句改为转述句,第三人称“ 他 ” 或 “ 她 ”和 为第一人称“ 我 ”互改,说话内容涉及第一人称应改为第二人称. 　　
如：老班长说：“ 我没有完成任务,没把你们照顾好.” 　　
改：老班长说,他没有完成任务,没把我们照顾好. 　　
4.再把引述内容改为转述句中,引述内容中如果有“这”,务必在改为转述句中把“这”改为“那”. 　　
如：小李对小何说：“我今天要批这些文件.” 　　
改：小李对小何说,他今天要批那些文件.

氦气.

对于这个问题天文学界是有争议的.因为太阳系范围就是太阳的引力控制范围.而我们知道万有引力随距离变小是没有界限的.就是说距离再远也不会变成0.那么存在多少太阳引力可以算作太阳系范围就有争议了.是可以捕获一颗质量1吨的小行星,还是可以捕获一粒1克的宇宙尘埃算作太阳系范围?现在一般来说多数科学家接受太阳系范围半径大概1光年.这可以说是相当远了.

汉魏太学,晋设国子学,隋设国子监

1632年,崇祯五年,按照清朝的要求,这应该成为皇太极的年号,天聪6年,而不应用崇祯的.
这是张岱晚年的作品,算是写的回忆.
此时明朝已经灭亡,但是他坚持用明朝年号,这就是对故国的怀念之情,就像清朝灭亡之后,很多遗老遗少坚持用宣统年号一样.

900/15=60
那么需要的数为61棵 两端都有
所以树苗数小于61
900/25=36
如果全部中满需要37棵
问题不完整不知道你想问什么
那就是25和15的公倍数 900以内的
25和15的最小公倍数为75 那么
900/75=12 两端各有一个坑 有13个坑是公用的
2、X-3/4=2（5/8）X求出来 算X/（3/4）就OK 了

顽强是指非常坚强,刚坚不屈；而倔强是指对待某一件事情不放弃.开头写倔强是为了引出生命不放弃的过程,而结尾的顽强是为了总结生命的不屈.

汉魏设（太学 ）.西晋改称（国子学 ）,隋又称（国子监 ）,从此国子监与太学互称,都是最高学府兼有教育行政机构的职能,就学的学生皆称（生员 ）

The first day of the lunar year old for New Year's day, commonly known as the "new", execute Gregorian calendar before Spring Festival. Cream-color On New Year's day morning, old, jiaxing residents to south XiaoCao erwang temple outside the burn incense, rob head ibiza, open the door the firecracker went off the sailors. Early in the New Year, to the elders to minor junior to BaiNianQian elders. BTW, take breakfast prevalence eat rice cakes "annual high" meaning, also have eat rice YuanZi, meaning "completely circle circle". In this day and CanNong sweep says "Saul silkworm flowers land", meet wishes each other "silkworm 24 points," flower unlikelihood cocoon harvest.
Do we call sugar, rice pudding. Haining, tongxiang area are playing glutinous rice pudding, big, waxy, Jiaxing in northern area do muffin primarily, called "wipe cake;" Jiaxing near mostly do "board sugar cake", the board mahogany, gingko wood carved to peach, carp, Pisces as patterns.
Is hair reguar bamboo shoots. MiGanShui bought frozen in Amoy, immerse the few days and nights, then in pot boil, then the hall permeates a thick old bamboo acid cooking gas, be like now village pervaded the diving in 17 taste as... Chinese New Year is winding bamboo shoots of burning flesh; Still another kind is a hoof, Pang Pang have hoofs walk oil and don't walk two cooked in oil. This is to celebrates New Year's eve flavor.