Remember to wash your hands __________ you have meals.
—Whose model plane is it?—It’s Jack’s. He made it by _______.
—Excuse me, can you give me a _______? —Sure.
—_______ I borrow your English book? —Yes, of course you _______.
Do you prefer _______?
—Mr. Hu, can you tell us how to learn swimming well?—Sure. But remember we can learn nothing well _______ hard work.