1. The modern mocroscope is no longer the mocroscope ____it was before.C
A which B whose C that D what
请问为什么不可以选则A?
2. One light year is the distance ___light travels in one year.A
A in which B that C as D what
我除了知道不选择D 其他我认为都可以啊
3.Mr Smith will move into his new house next Mondey , ___it will be completely finished.
A by that time B by which time C by then D by the time
这道题正确答案我都不知道 请详细讲解一下每个选项
4.I am pleased with what you have given me and ___you have told me.B
A that B all that C which D all what
这道题为什么不可以选择 A 我知道ALL 必须和THAT 但是如果不用ALL 不可以吗？
5.More niddle_aged persons suffer from heart trobule___is generally believed.C
A which B that C as D than
ABC 不是都可以做主语吗 为什么要选择C?

1. The modern microscope is no longer the microscope ____it was before.C
A which B whose C that D what
请问为什么不可以选则A? 这里不是定语从句，that在这里作microscope的同位语

2. One light year is the distance ___light travels in one year.A
A in which B that C as D what
定语从句，in which即in the distance（light travels in the
distance光在这段路程里穿梭），which替代了the distance

3.Mr Smith will move into his new house next Monday , ___it will be completely finished.
A by that time B by which time C by then D by the time
选B，史密斯先生将在下周一搬进他的新家，到那时新家已经完全完工了。
by the time到...时候，这句是定语从句，只能选B

4.I am pleased with what you have given me and ___you have told me.B
A that B all that C which D all what
what＝all that，这里不用all不可以，除非你继续用what，因为be pleased with＋名词或者名词性短语，这里what you have given me 是一个名词性短语all that you have told me也是一个名词性短语，直接用that you have told me 的话就是个从句了

5.More middle-aged persons suffer from heart trobule___is generally believed.C
A which B that C as D than
从意思上理解，as在这里表示正如。正如大所相信的，更多的中年人遭受心脏病。