楼上说的两点很有道理,我都同意.但是这里当that本身作为先行词时我觉得后面的关系词which即使做宾语也不可以省略.虽然不记得有语法书上面谈到这一点,但是觉得如果省略后读起来很别扭.我能想到的一个例句是I would like to keep that which you gave me yesterday.如果作宾语是应该可以省略,但是这句里如果去掉后面的which就感觉不对了I would like to keep that you gave me yesterday.就要把that换成what才通顺.I would like to keep what you gave me yesterday.