—Excuse me, Maria. Can I use your bike?—Sure. Here you are. But you must return it _____ time.
--- Good morning, class!! A. Hello B. Good morning, Li Lei C. Good morning, Miss Fang
British students have________ weeks ________ in the summertime than Chinese students.
workers in the factory over two thousand.
You read his books, and he wants to read your books ____.
They will build nature reserves _____ protect ______ birds.