单项选择。
一 do you eat dinner? 一At 7:00 p.m.[ ]
A. What
B. When
C. How
答案：B
What a pity! Considering his ability and experience, he ___________ it better.
A．need have done
B．must have done
C．can have done
D．might have done
高压开关柜外绝缘应满足的条件。
