用机上数据装载机下载数据整个过程中,是否需断开系统跳开关?
A、是
B、否
参考答案：B
数学竞赛题共20道．每做对一题得8分，做错一题倒扣4分．小丽得了100分，她做对了______道题．
My new pen ______. Who ______ have taken it?
A．has been disappeared; can
B．has disappeared; could
C．is missing; should
D．has been lost; may
