问题
选择题
The boy often gives a satisfactory answer to the teacher’s question，__________ just a minute.
So he’s usually the teacher’s pet.
A．thought
B．having thought
C．and to think
D．thinking
答案
B
-ing形式短语作状语,且think(思考)表示的动作发生于give a satisfactory answer之前,故用having thought。