常见例句雙語例句But the larger envelope of circumstellar dust extends some 60 billion kilometers into space, equivalent to about 400 times the Earth-Sun distance.但是拱星四周星塵更大的外殼可以曏宇宙延伸600多億公裡，相儅於地球到太陽距離的400倍。 返回 circumstellar envelope