当M＜1向M＞1变化时，喷管截面的变化规律是（）。
A.渐扩
B.渐缩
C.缩放
D.达到最小值
参考答案：C
He was unhappy when he sold his guitar.After all，he________it for a very long time.
(2013·辽宁，22)
A．has had
B．had had
C．has
D．had
— Do you want coffee or tea, Jim?
— ______. [ ]
A. Yes, coffee
B. No, I don't
C. Coffee, please
D. Yes, I'm thirsty
