He ________ be tired, because he began to work just ten minutes ago.
A. needn’t
B. mustn’t
C. may not
D. can’t
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Mike ______ be in Beijing because I saw him in the classroom only a few minutes ago.
A. mustn’t
B. can’t
C. may not
D. might not
- This kind of bananas is ________.- Yes, it tastes very _________.
A. good; nice
B. well; nice
C. good; nicely
D. well; nicely
病原体进入人体后,仅引起机体发生特异性免疫应答,病理变化轻微,临床上不显出任何症状和体征,只有通过免疫学检查才能发现者,称为( )
A. 隐性感染
B. 轻型病例
C. 病原携带状态
D. 恢复期病人
E. 潜伏性感染
下列选项不属于显性感染的表现的是( )
A. 引起机体发生免疫应答
B. 无血液生化改变
C. 出现临床症状,体征
D. 有病理改变
E. 脏器功能改变