加强焊工个人防护，定期进行身体检查，以预防（）。
A、职业病
B、感冒
C、发热
参考答案：A
The retired teacher is said to have returned from the USA, where he ______ by some of his old students.
A．would be visited
B．visited
C．had been visited
D．have been visited
外感头痛的病因（）
A.以燥邪为主
B.以热邪为主
C.以风邪为主
D.以寒邪为主
E.以湿邪为主
