There are lots of things I need to prepare before the trip.A. whoB. thatC. whatD. whom

问题补充：

There are lots of things I need to prepare before the trip.

A. who

B. that

C. what

D. whom

答案：

A. who

(答案→)B. that

C. what

D. whom

解析：

这题考查定语从句的用法，that引导定语从句修饰things，who、whom引导定语从句只能修饰人，what不能引导定语从句。所以填B。