—You won't enjoy it_________ you put your heart into it.
A:when
B:if
C:after
D:unless
a、b两个物体在同一直线上运动,它们的v﹣t图像如图所示,在t1时刻( )
-- Is this shirt ____ (she)?
-- No, it's ____ (you).
___swim? Yes, I can.
①后来,大象又偶到了小羊____
②青蛙想,要是在泥塘周围种些草,就能买出去了。____
③小免子说:“咦,大象啊,你的耳朵怎么耷拉下来了?”____