Jack, what’s your main reason for choosing one restaurant ______ another?

Gun control is a subject ______ Americans have argued for a long time.

__________the window, please. –OK. Now you see the window _______.

It’s a long way to go！We must take a taxi.—________for a taxi.The underground cansave money.

Half of the class _____ done most of the work ．The left _____ rather difficult．