A:吸气冲程
B:压缩冲程
C:做功冲程
D:排气冲程
如图所示为某简谐运动的图象,若 时,质点正经过O点向b运动,则下列说法正确的是( )
It was not until dark ___ he was aware of ___ he thought was the correct way to solve the problem.