定语从句中 先行词是those 用THAT还是which引导

Question

先行词是those 时用什么
列:Don't hesitate to do those -----are worth doing
为什么一定用that

Answer 1

只可用that.
下列情况只可用“that”而不可用“which”：
1. 序数词或最高级形容词或叙述此修饰先行词，如first,best
2. 先行词是all, little, much, few, anything,
nothing, something, none, the one时
3. 先行词被any, few, little, all, no 修饰时
4. 先行词被the only, the very, the same,
the last修饰时
5. 先行词既有人又有物时。
6. 当句中已有who时，为避免重复。
高中阶段知道这些就可以了。

Answer 2

如果先行词those 指人关系词则用who
those who finished the job should be praised.
先行词为 that/those 指物时用which

Answer 3

这是肯定的，只可用that

Answer 4

which that 都可以

Answer 5

that