烟是生产性毒物的一种较常见的存在方式,其直径是()。
A.<0.1μm
B.0.1~0.5μm
C.0.5~1.0μm
D.1.0~5.0μm
E.>5.0μm
参考答案:A
下列能使牛奶变成酸奶,使蔬菜变成有酸味的泡菜的是[ ]
A.酵母菌
B.乳酸菌
C.霉菌
D.枯草杆菌
--__________ was it_________ they discovered the entrance to the underground place?
--Totally by chance.
A.How; that
B.What ; that
C.When; when
D.Where; that