She set off at 9 a.m. and ____ the airport an hour later.
_______ from the hill, the whole city of Nanjing looks more beautiful.
____ I saw her, I remembered to give Marie the money I owed her.
―Who are those people walking along the street with banners? ―A group _______ itself the League for Global Environment Protection.
_____ human beings live in great numbers, the waters are very likely to become contaminated.
_____ I admit that the problems are difficult , I don’t agree that they cannot be solved.