喷吹系统各罐和煤粉仓内煤粉存放时间不许超过（）。
A.2小时
B.4小时
C.6小时
参考答案：B
—You’d better _________ some popcorn or soft drinks before the film begins.
—But I think it’s better _________ anything while watching the film.
A．buy; not have
B．to buy; not to have
C．to buy; not have
D．buy; not to have
保温材料
