由此你可以算出银河系的总质量。From this you can calculate the total mass in the Galaxy.银河系由1,000亿颗恒星组成。The Galaxy consists of 100 billion stars.地球是银河系中的星球之一.The earth is one of the planets in the Galaxy....
...efforts to find homes for people despairing of ever having a roof over their heads...为那些对有瓦遮头不再抱有任何希望的人们找到住处的努力No one ever reads these articles, least of all me...从没有人读这些文章，我就更不用说了。I know of no professional person who...
No plea can be set up on the ground of ignorance.以无知为理由而提出的抗辩是不能成立的.He left on the ground of ill.他以生病为理由离开了.The youngster has been excused by the law on the ground of his youth.这个青年由于年轻而受到法律的赦免....