中国公民应当从对外开放的或者指定的（）出境、入境。
A.国家
B.城市
C.机场
D.口岸
参考答案：D
Mr Li is a good teacher. He always makes his class _____.[ ]
A. lively and interested
B. lively and interesting
C. alive and interested
D. alive and interesting
干性霍乱
