单选题
Why do we measure the distance in light-years instead of miles?
A、
Units of light-years sound better.
B、
Using light-years reduced the number of figures used.
C、
We used to measure distance in light-years long ago.
D、
We do not make mistakes when we use light-years.
【正确答案】
B
【答案解析】
推理题。宇宙中星球之间的距离十分遥远，用英里计算，数字会十分巨大，所以用光年计算较为简便。
提交答案
关闭