People from the West like to use such expressions as “please” and “thank you” in cases ______ some people in Asia may not think it necessary.

A．what

B．which

C．that

D．where

局部浸润麻醉常用的药物是（）

A.1％丁卡因

B.2％丁卡因

C.5％普鲁卡因

D.2％利多卡因

E.1％利多卡因