If planet A takes two years to revolve once round its sun,and planet B takes one year,when will they

题目

If planet A takes two years to revolve once round its sun,and planet B takes one year,when will they next both be in line with the sun

答案

行星A绕太阳转一圈要2年,行星B绕太阳转一圈要1年,它们下一次与太阳在一直线上是什么时间答案：一年后 In one year