Tina didn't come to school yesterday because she _________ a bad cold.
A:made
B:wanted
C:had
D:took
一个物体从光滑斜面的顶端由静止开始下滑,斜面长10m,倾角θ=30°,斜面静止不动,物体的质量M=2kg,重力加速度g取10m/s2.求:
亲→____→____
张→____→____
农→____→____
产→____→____
山→____→____