假设摩托艇受到的阻力的大小正比于它的速率,如果摩托艇发动机的输出功率变为原来的2倍,则摩托艇的最大速率变为原来的( )
A:4倍
B:2倍
C:3 倍
D:2 倍
— Did you enjoy____ (you) at the concert?
— Yes, I enjoyed ____ (listen) to music all the time.