该患者可能的诊断是
A．肺气肿
B．支气管哮喘
C．自发性气胸
D．心源性哮喘
E．气管异物
参考答案：B
The man we followed suddenly stopped and looked as if ______ whether he was going in the right direction.
A．seeing
B．having seen
C．to see
D．to have seen
1987年，中国共有（）个项目入选《世界遗产名录》。
A.4
B.5
C.6
