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
参考答案：C
He said _______, but actually he didn’t keep his promise. That’s to say, he didn’t show up.
A．he would come the next day
B．he had come tomorrow
C．he came the next day
D．he will come tomorrow
圆弧挡料板与斗轮体之间的常用间隙是（）。
A、3-5mm；
B、1-8mm；
C、2-7mm；
D、0.2-0.7cm。
