穿透力弱，不适于作表面麻醉的是
A．利多卡因B．普鲁卡因C．丁卡因D．布比卡因E．丙胺卡因
参考答案：B
Is it the country ______ you studied ______ you are going to visit next week?
A．in which; which
B．where; that
C．that; that
D．which; that
加热器水位太低，疏水端差会（）。
A.减小；
B.增大；
C.不变；
D.无法确定。
