问题补充:
When Peter speaks in public, he always has trouble _ the right things to say.
A. thinking of
B. to think of
C. thought of
D. think of
答案:
(答案→)A. thinking of
B. to think of
C. thought of
D. think of
解析:本题考查固定搭配,have trouble in doing sth.做…有困难,in可以省略,句意:当彼得在公共场所讲话时,他总是找不到适当的话说。所以答案为A。