把质量相等的水和酒精，分别装在完全相同的圆柱形容器中，则水和酒精对容器底部的压强一定是相等的。[ ]
√
三次痰涂片及一次培养阴性的肺结核称（）
A.传染性肺结核
B.非传染性肺结核
C.菌阴性肺结核
D.原发型肺结核
E.闭合性肺结核
Students in English-speaking countries usually address their man teacher ‘sir”, but __________ their woman teacher “madam”.
A．seldom they address
B．do they seldom address
C．seldom do they address
D．they seldom do address
