若病人出现声音嘶哑，应考虑
A．肿物侵犯喉上神经
B．肿物侵犯喉返神经
C．肿物侵犯气管
D．因肿物造成食道狭窄
E．出现食管气管瘘
参考答案：B
简述抗体再次应答的特征。
—How often do you call your parents?
—______, but usually once a week.
A．Forget it
B．Once in a while
C．It depends
D．I’ve no idea
