题目

根据短文理解，选择正确答案。 Humans have launched themselves into the outer space. They've landed on the moon. They've built habitable space stations that orbit the Earth. The next giant leap for mankind is to reach another planet – specifically, Mars. The problem is that it's no easy task. The planet is 586 times further away from the Earth than the moon, and it'll take around 180 to 220 days to reach Mars, depending on where each planet is in its orbit. Such long periods in space have suggested many potential health problems, including hormonal changes, skin conditions, and m甲、乙两人同时从同一起跑线出发，同向做匀速直线运动，某时刻他们的位置如图所示，图中能正确反映两人运动距离与时间关系的是（ ）A．B．C．D．