求助几个问题

1.The spraying of pesticides can be carefully planned, but accidents, weather conditions that could not be foreseen, and pilot errors often cause much larger deposits of spray than anticipated. (A-P1-33)

关于could，在白勇语法上看到在陈述句中只有时态的区别，这里为什么能用呢？

2.Nowhere in Prakta is the influence of modern European architecture more apparent than in its government buildings. (B-p80-18)

这句话到底什么意思还没太弄明白。

3.The man was always aware, sometimes proudly and sometimes resentfully, that he was a small-town Midwesterner thrust into a world dominated by wealthier, better-educated, and more polished people than he. (E-P75-11)
这个thrust是-ed分词形式嘛？

4.Once positioned in space, the Hubble Space Telescope will capture light from source twenty times fainter than those that can be detected by ground-based instruments. (A-P1-57)

想问一下light 是复数嘛？为什么用those？

4.. Since the movie was released ，seventeen UFOs have been sighted in the state , more than had been sighted in the past ten years. (A-P1-168)

(注意时态，按时间先后顺序)

特别注意:

一般情况下 in the past ten years用在现在完成时态中，这里根据逻辑意思，用了过去完成时态。.

这标的题号怎么都看不懂...

2。原型是 the influence of modern European architecture  in Prakta's nowhere is more apparent than in its government buildings.

我觉得是说这个影响在p的政府建筑中最为显著

3.thrust 好像三态都一样 这里应该是过去分词

其他的最好能提供以下完整原题或者说明下是什么地方的题...好像都做过，记不得在哪了...