3.（D)The book was so interesting that he had read it for three hours_____he realized it.为什么选D?
4.（D)____you can't answer this question,we have to ask someone else for help.
5.He is _the best____(good) at English in his class.
1.玻璃杯,glass 两个玻璃杯,two glasses 两杯水,two glasses of water
3. read用了过去完成时,说明发生在realize之前,所以用before.