【单选题】If someone says, "It cannot hurt to ask." he means ______________.
A.
it's a good idea to ask.
B.
he doesn't want to ask.
C.
it will hurt if he asks.
D.
he's not sure whether to ask or not.
【单选题】继发型肺结核与原发性肺结核的主要不同点是
【判断题】MOOC是一种以开放访问和大规模参与为目的的在线课程,其中“开放”指任何一个学习都可以付费注册任意课程进行学习。
【单选题】Mr. Zhang is the best music teacher in our school, but he has hurt his left foot and cannot ________tomorrow’s concert.
【单选题】. The best music teacher in the school has hurt his left foot and cannot ______ tomorrow’s concert.
【单选题】按钮联锁正反转控制电路的优点是操作方便,缺点是容易产生电源两相短路事故。在实际工作中,经常采用( )正反转控制电路。
【单选题】188. 按钮联锁正反转控制电路的优点是操作方便,缺点是容易产生电源两相短路事故。 在实际工作中,经常采用( )正反转控制电路。
【单选题】近年来兴起的慕课( mooc)指的是( )