正电胶钻井液的pH值应控制在()之间。
A、4~6
B、6~8
C、8~10
D、10~12
参考答案:C
Because the shop_____, all the T-shirts are sold at half price.
A.has closed down
B.closed down
C.is closing down
D.had closed down
电算化会计信息系统中常见的硬件结构有()
A.单机结构
B.多机松散结构
C.多用户结构
D.微机局域网络