—_____ your brother play basketball, John?

—No,  he _____. [ ]

A. Is; isn't

B. Can; can

C. Can; can't

D. Are; aren't

MKS-5钻机油箱上的截止阀要先行（），否则不准电机。

A、打开，启动

B、打开，停电机

C、关闭，启动

D、以上都不正确