30. Last month, the Japanese government expressed their thanks for the aid they ______ from China.

A. receive                 B. are receiving         C. have received        D. had received

分析：D。本句意为：上个月，日本政府表达了他们从中国得到的援助。从时间上看，应该是先得到援助，然后才表示感谢，由于“表达”用的是一般过去时（expressed），所以“得到援助”就应用过去完成时（had received）。又如：

He was conscious that he had annoyed his boss. 他意识到他惹烦了上司。

Although he had only entered the contest for fun, he won first prize. 尽管他参加这次竞赛只不过是闹着玩儿而已，却赢得了头奖。

31. We arrived at work in the morning and found that somebody ______into the office during the night.

A. broke                   B. had broken            C. has broken            D. was breaking

分析：B。从时间上看，肯定是先有人在夜间闯进了办公室，然后才会有人发现这个情况。由于“发现”用的是一般过去时（found），所有夜间“闯进”办公室，就应用过去完成时（had broken）。又如：

I went home directly I had finished work. 我一干完工作就回家了。

32. By the time Jack returned home from England, his son ______ from college.

A. graduated             B. has graduated        C. had been               D. had graduated

分析：D。本句意为：当杰克从英格兰返回家时，他的儿子已经大学毕业了。显然，儿子大学毕业在先，杰克返回家在后。而“返回”家用的是一般过去时（returned），故儿子大学毕业要用过去完成时（had graduated）。又如：

I read that he had resigned. 我看到他已辞职的报道。

The weather was rather worse than I had expected. 天气要比我预料的还坏。

33. She was surprised to find the fridge empty; the child ______ everything!

A. had been eating     B. had eaten              C. have eaten            D. have been eating

分析：B。句子前面说她发现冰箱是空的，她感到很吃惊，而冰箱为什么是空的呢？是因为里面的东西都被孩子们吃掉了。显然，孩子们吃掉冰箱里面的东西在先，她发现这个情况在后，而She was surprised to find the fridge empty用的是一般过去时，故孩子们“吃掉”冰箱里面的东西要用过去完成时（had eaten）。又如：

That the attempt to save her had failed soon became widely known. 想救她而未救成，此事不久已尽人皆知。

I was surprised when I saw the farm. I had imagined it to be much bigger. 我看到那个农场时很吃惊，我原认为会它会大得多。

34. —What a mistake!

—Yes. I ______ his doing it another way, but without success.

A. was suggesting      B. will suggest           C. would suggest       D. had suggested

分析：D。根据句中的What a mistake（真是个愚蠢的错误）和without success（没有成功）可知，“没有成功”的情况已经发生了。为什么说是个愚蠢的错呢？为什么没有成功呢？原来是说话者建议他用另外一种方法来做，很显然，“建议”他用另外一种方法来做在先，他照去做并且没有成功这件事在后，所以“建议”这个动作应用过去完成时（had suggested）。又如：