下列哪种是被动免疫的生物制品（）
A.伤寒菌苗
B.卡介苗
C.麻疹疫苗
D.白喉类毒素
E.破伤风抗毒素
参考答案：E
横梁的主要作用是（）导卫装置。
A: The wind will probably get up later.B: ().
A. still, another month should see us through the worst of the weather.
B. It seems to be clearing up.
C. As long as it doesn’t rain.
D. Fairly mild for the time of year.
