She studies ___ medicine before she turned ___ writer.
A.×; ×
B.the, a
C.×; a
D.the; ×
答案:A
干热风
磁翻板液位计投入运行时,应()
A、先开下阀门,然后快速开上阀门
B、先开下阀门,然后慢慢开上阀门
C、先开上阀门,然后慢慢开下阀门
D、先开上阀门,然后快速开下阀门