问题
选择题
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
解题关键：have trouble in doing sth，此处in可以省略。句意：当Peter当众讲话的时候，他总是很难想起该说的话。
【考点定位】考查非谓语动词的用法。