A:had known; I thought
B:have known; had I thought
C:would know; I would think
D:knew; did I think
汽车在平直公路上以10m/s的速度做匀速直线运动,发现前面有情况而刹车,获得的加速度为2m/s2,则汽车经过3s时速度的大小为____ m/s;经10s时速度的大小是____.
抗日战争中,国民党军队抗战以来取得的最大胜利是( )