埋弧焊机控制系统测试的主要内容是()。
A、测试送丝速度
B、测试引弧操作是否有效可靠
C、电流和电压的调节范围
D、测试小车行走速度
参考答案:A, B, D
— Can I pay the bill by check?
— Sorry, sir. But it is the management rules of our hotel that payment ______ be made in cash. [ ]
A. can
B. shall
C. will
D. may
饮食消费