疣状口腔白斑多发生于（）。
A.口底
B.舌腹
C.口角
D.牙龈
E.上腭
参考答案：D, E
Jenny suggested our going on an outing to the countryside next weekend, but the rest didn’t sound very _________ about the idea.
A．anxious
B．enthusiastic
C．cautious
D．secure
工作描述是（）沟通的一个例子。
A.上行
B.下行
C.水平
D.对角线
next weekend, but the rest didn’t sound very _________ about the idea.