Question

求助英语高手

Over a very large number of trials, the probability of an event's occurring is equal to the probability that it will not occur.为什么是event's occurring 而不是event will occur和后面一致，还有 over都有什么用法，什么情况下使用它，有句话是By the middle of the twentieth century, painters and sculptors in the United States had begun to exert a great worldwide influence over art.为什么用over不用on

Answer 1

第一句：over在。。之中（参考楼上）介词
第二句：exert a great worldwide influence over、on art
over 和on 都可以，但是over的范围更大，表示覆盖，说明对其影响非常大，介词。
the probability of an event's occurring= the probability that an event will occurr。
that引导同位语从句，这里考的恰恰不是平行结构，而是避免重复。
希望能帮到您。

追问

我不明白怎么是同位语 能给我详细解释一下么？

追答

同位语从句，就是将一些抽象名词具体化，如：
The news( that he will come back soon） makes me excited.译：这个他马上就要回来的消息让我很是兴奋。
括号里的是that引导的同位语从句，所谓“同位语”，顾名思义，就是二者的位置都是充当主语的。在这里就是the news和that he will come back soon二者其实都是一样的意思，一样的位置。同位语从句一般都用that引导，并且that不能省略。
另，还有一些可以具体化的抽象名词有:report,indicate等

Answer 2

1 over(==among / in ) a very large number of trials,
2 to exert a great worldwide influence over(==on / upon) art
3 the probability of an event's occurring(动名词结构)= the probability of an event that will occur（定语从句结构）
意义相同，只是选词不同---------They are the same in meaning but different in diction.Simply a matter of personal preference

Answer 3

1.动名词作主语。
2.over 解释为 从头到尾，强调一个过程。

3.over ,on都可以的.
不要太钻牛角尖。