感染艾滋病病毒(HIV)的孕妇引起胎儿感染,这是经()
A.医源性传播
B.垂直传播
C.食物传播
D.接触传播
E.飞沫传播
参考答案:B
There is much truth in the idea _ kindness is usually served by frankness.
A.why
B.which
C.that
D.whether
已实施装运前检验的货物,入境时无须再报检。( )