About of the workers in the factory were born in the .
一质点做匀加速直线运动,在时间间隔t内位移为s,速度变为原来的3倍.该质点的加速度为( )
下列有关波浪能的特点,正确的是( )
①清洁 ②可再生 ③分散 ④发电量稳定