液压起货机使用完毕，先关（）再关（），停止供电，最后关闭高压油泵阀门。
A.辅助油泵；主油泵
B.主油泵；辅助油泵
C.辅助油泵；高压油泵
参考答案：B
我国成人氟的适宜摄入量（AI）为（）
A.0.5mg／d
B.1.0mg／d
C.1.5mg／d
D.2.0mg／d
E.2.5mg／d
She has set a new record，that is，the sales of her latest book _____ 50 million.
A．have reached
B．has reached
C．are reaching
D．had reached
