It was not until nearly a month later _________I received the managers reply.

A．since

B．when

C．as

D．that

钩端螺旋体的传播途径主要是（）

A.呼吸道吸入

B.粪-口途径

C.破损的皮肤入侵

D.昆虫媒介叮咬

E.母婴垂直传播