语法疑惑(4)

carefield

XDF, 三册, 94.10 SEC2

13. His studeies of ice-polished rocks in his alpine homeland, far outside the reange of present-day galciers, led Louis Agassize in 1837 to propose the concept of an age
(in which great ice sheets had existed in now currently temperated areas.)

KEY; in which great ice sheets existed in what are now temperate areas.

这题虽然用习语可以分出答案, 但我不明白为什么改成了过去时呢? AN AGE 应该是过去的过去, 不应该用完成时吗? 谢谢

12. Nuclear fusion is the force that powers the Sun, in stars, and hydrogen bombs, (mearing the nuclei of atoms and not spiliting them apart, as in nuclear reactions)

C merging the nuclei of atoms rather that spliting them apart, as nuclear reactors do.

D and merges the nulei of atoms, unlike atom reactors that split them apart.

请问如何区分VING 和 THAT 从句呢? 我当时选C, 认为 MERGING 是对主要动词的说明;

另外E 中的UNLIKE会不会引起歧义? 修饰NULEAR FUSION OR ATOMS?

albert

1. 我觉得过去时态和过去完成时态这里强调的东西不同。

如果强调动作的先后，如：propose发生在...之后，用过去完成时态。
如果强调一个concept,即过去的一个既定事实状态。。用过去时态。

所以这里用时态进行判断不保险。。改错经常会出现这样不保险的情况，所以知道越多其他错误，从另一个角度进行思考和验证才比较保险。

2. merge 从意思上不应该是修饰(如伴随或者结果) 动作power,而是并列。。从逻辑上理解两个动作的关系很重要。

nina23

2. the subject of "merge" is not Nuclear fusion but force.so we use "merges" .

albert

同意。。这里的主干是 ...is a force....主要动词是is

carefield

多谢ALBERT, NINA, ALBERT 换了个新ICON, 真逗.
1. 以后对时态要小心使用

2.第二题, 可是要分清主语是fusion or power, 也不容易呀, 我怎么觉得两者都可以呢? 也许从动词与动词之间的关系来判断更好一点.