乘坐游乐园的翻滚过山车,质量为m的人随车在竖直平面内旋转时,下列说法正确的是( )
A:车在最高点时,车在轨道内侧,人处于倒坐状态,被保险带拉住,没有保险带,人就会掉下来
B:人在最高点时对座位仍可能产生压力,但压力一定小于mg
C:人在最低点时对座位的压力等于mg
D:人在最低点时对座位的压力大于mg
Danny:I'm hungry. ____!There is a restaurant.
Jenny: ____. I am not hungry. I don't want to eat.
Danny:Go with me,please!
Jenny:Okay!
Danny:I'm excited.
Jenny:Danny,please don't ____!Don't ____! Don't ____!
Danny:Okay!Okay!I walk.
在五带中,既无太阳直射又无极昼极夜的是( )
一课外小组在夜晚定点定位(即望远镜固定不动)观测某一恒星位置,据此回答下题.