摘要
太阳系已经不再神秘。你知道九大行星的故事吗?Which is the coldest planet?Pluto[冥王星] is nearly 40 times as farfrom the Sun as Earth is, and tem-peratures there drop to a very icy-235℃!That’s more than 2.5 timescolder than the coldest place onEarth.It is the coldest planet!
