题干
37. No one has come up with a better explanation of why dinosaurs ______.
A：died away
B：died for
C：died of
D：died out
答案(点此获取答案解析）
D
A：died away
B：died for
C：died of
D：died out
的光滑斜面上，由底端向顶端做匀加速运动。当物体运动到斜面中点时，去掉推力，物体刚好能到达顶点，则推力的大小为（ ）
