有机体缺乏某种东西所引起的内在促动力量是()
A.动机
B.驱力
C.需要
D.渴望
参考答案:B
连词成句。
1. old your how is mother (?)
2. is how your room large (?)
3. wants to he football play (.)
4. my smaller is bag Tom's than (.)
5. pencil 20 cm my is long (.)
边长为10 cm的正方体浸没在水中,受到的浮力是______N;浸没在煤油中受到的浮力是______N(煤油密度是0.8×103kg/m3 g=10N/kg).