I’d appreciate ______ if you could let me know in advance whether or not you will come.
—I can never forget the day ___ we spent together in the summer camp.—Well, especially the day _______it suddenly began to rain in the middle of the night.
Every one of us must know this: _________ we live can we save the earth.
During the period of recent terrorist activities, people _____ not to touch an unattended bag.
—What a great cook your sister is! —Yeah! We ______ never have enough of her cookies.
It is difficult to find a satisfying job today.This job is great ________ salary, but it has some disadvantages.