能固精、缩尿、止泻，平喘的药物是（）
A.白果
B.菟丝子
C.沉香
D.补骨脂
E.龙骨
参考答案：D
桥梁总跨径是多孔桥梁中各孔（）的总和。
A.净跨径
B.计算跨径
C.理论跨径
D.标准跨径
The boy asked his father ______________________ .
A．where it happens
B．when did it happen
C．what did it happen
D．how it happened
