小儿迁延性腹泻的病程是()
A.2周以内
B.2个月以上
C.2周至2个月
D.半年以上
E.以上均不对
参考答案:C
We were so struck of ____ beauty of _____ nature that we stayed on for another two weeks. [ ]
A. the , the
B. /. The
C. the , /
D. a , the
小芳在水平面上用50N的水平推力,加速推着一辆重120N的小车,前进了10m,小芳的推力做功______J,水平面对小车的支持力做功是______J.