某男,40岁,每天睡眠时间5~6小时,无其他症状,不影响工作,查体正常,考虑为
A.不寐
B.暂时性失眠
C.生理性少眠
D.老年人生理状态
E.其他病影响
参考答案:C
—Let's go to play soccer this afternoon, Jack.
—Sorry, I ______ a piano lesson. [ ]
A. had
B. am having
C. didn't have
D. am not having
下列哪项不是霍乱弧菌的致病因素()
A.鞭毛
B.菌毛
C.荚膜
D.肠毒素
E.内毒素