Q-6-105D型蓄电池的液面高度应高出极板（）。
A、10~15mm
B、15~20mm
C、20~25mm
D、25~30mm
参考答案：A
He used to in a small village , but he has been used to in a big city .
A.live, living . B. live, live. C. living , living.
1Cr18Ni9Ti奥氏体不锈钢中含铬为（）%
A.40
B.18
C.25
D.30
