Go and make someone laugh —just might help them live longer.A. itB. whichC. thatD. they

问题补充：

Go and make someone laugh —just might help them live longer.

A. it

B. which

C. that

D. they

答案：

(答案→)A. it

B. which

C. that

D. they

解析：考察代词用法。因为句中用的是破折号，所以排除B。It 代指上文提到的同一个事物。此处代指的就是go and make someone laugh， that 代指可数名词单数，或者不可数名词，特指。与前文提到的东西是同一类而不是同一个。They代指的是可数名词复数。