①____ A.read B.play C.book ②____ A.Friday B.Wednesday C.birthday
③____ A.sports B.Monday C.Friday
④____ A.weekend B.science C.music
⑤____ A.maths B.often C.Chinese
a、b两物体从同一位置沿同一直线运动,它们的速度图象如图所示,下列说法正确的是( )