His ability ( )in those years was praised by all.

1.The way he had the problem ___his ability
1）结构分析：这是主从复合句
主句：The way showed his ability 该方法显示了它的能力
同位语从句：（that省略）he had the problem settled 即他使得问题被解决的方法
2）选项解析：
动词过去式 settled 是同位语从句的谓语动词；动词过去式 showed 是主句的谓语动词；如果用现在分词 showing,则主句缺了谓语动词.
2.Without your help,I ___ my final exam.
1）would have failed 是对过去的虚拟,选用表示“要是没有你的帮助,我当时的考试就不会通过”,言外之意是考试已过,我也通过了.
2）would fail 是对将来的虚拟,选用则表示“要是没有你的帮助,我的以后的考试就不会通过”,言外之意是考试还没有进行,你的帮助也许会使我通过考试.
3.Had he paid more effort last year,he ____a college student now.
这是个错综虚拟条件句,从句用 had paid 指的是 last year,主句用would be 指的是现在.
翻译成汉语：假如你去年付出更多的努力,现在你就是大学生了.
4.I know I could not complete the task___填until the boss has come怎么错了
应该用 unless the boss had come
解析：该句是多重复合句：
第一重：I know 后面带的是宾语从句,
第二重：宾语从句是附加条件从句的主从复合句
主句——I could not complete the task 我就不能完成任务.
条件从句——unless the boss had come 如果不是老板来.
5.He made another wonderful discovery,_ of great importance to science.
1）which I think it is 关系代词which 指代的是 discovery,代词 it 同样指代 discovery,犯了重复错误.
2）which I think is of great importance to science 中关系代词是think 的宾语；of great importance = a discovery of great importance,省略了重复词汇.
3）翻译：他又做出一个令人惊奇的发现,我认为这个发现（是）对科学有十分重大的意义（的发现）.

A,setting做problem的定语从句,因为是主动态,所以用ing； show跟前面的时态had（过去式）,所以用showed