最大秤量20t的电子汽车衡，检定分度值为10kg，进行鉴别力测试时应使用多少砝码？
参考答案：进行鉴别力测试时应使用1.4d的砝码
10×1.4=14kg
根据问句选择正确答语。
( )1. Has Mr Li ever been to Hong Kong?
( )2. Have you ever traveled by ship?
( )3. Have they ever been to the moon?
( )4. Has Lucy ever been to the USA?
( )5. Have you ever gone surfing?
A. No, but they'd like to go there one day!
B. No, I haven't.
C. Of course! She comes from America.
D. Yes, he has been there several times.
E. No, I've only traveled by train and plane.
潜污泵（）之间是静密封。
A.电机输出轴与泵体
B.电缆和接线盒
C.上下壳体
D.电机壳体与泵体
