单臀先露的两下肢姿势是
A.髋关节届曲,膝关节屈曲B.髋关节直伸,膝关节直伸C.髋关节直伸,膝关节屈曲D.髋关节屈曲,膝关节直伸E.以上都不是
参考答案:D
Not until all the fish died in the river, _______ how serious the pollution is. [ ]
A. did the villagers realize
B. the villagers realize
C. the villagers did realize
D. didn't the villagers realize
根据温度、热量、内能的关系,下列说法正确的是: [ ]
A.温度高的物体含有的热量多
B.物体温度升高,一定吸了热
C.0℃的冰没有内能
D.物体温度升高,内能一定增加