最高泵压为40MPa,那么需安装测量范围为()的压力表。
A、0~50MPa
B、0~40MPa
C、0~70MPa
D、0~60MPa
参考答案:D
海陆漂移学说最早提出的是( )
A.麦哲伦
B.哥伦布
C.魏格纳
D.拿破仑
Betty sends _____ grandmother a card on her birthday. [ ]
A. she
B. her
C. he