丁卡因常用作表面麻醉是因为（）
A.局麻效力强
B.毒性较大
C.对黏膜的穿透力强
D.作用持久
E.比较安全
参考答案：C
270×0.4×2×2.5×0.5．
There（）a basketball match this afternoon.
A.is going to be
B.is going to have
C.is going to is
D.is going to has
