新指南中强调CPR时胸外心脏按压的重要性，要求按压中断不应超过的时间是（）
A.5秒
B.10秒
C.15秒
D.20秒
E.25秒
参考答案：A
电梯检修速度不允许超过（）ｍ/ｓ.
A.0.25
B.0.5
C.0.63
D.1
--Could you tell me ________?
---Yes. They ________ to the museum.
A．where the girls are; have gone
B．where were the girls; have been
C．where are the girls; have gone
D．where the girls were; have been
