题目

Early to bed, early to rise, makes a man healthy, wealthy and wise. This is an old English saying. Have you heard of it before? It means that we must go to bed early and get up early in the morning. Then we shall be healthy. We shall also be rich (wealthy) and clever (wise). This is true. The body must have enough sleep to be healthy. Children of young age should have ten hours’ sleep every night. Children who do not have enough sleep cannot do their work very well. They will not be wise and they may not become wealthy! The body also needs exercise. Walking, running, jumping, swimming and如图所示（甲）是某物体运动的s-t图像，则图（乙）中能与之相对应的v-t图像是（ ）