Swimmers must be very strong in order to build up speed because of the high resistance(阻力) of the water. Runners, , must struggle against the heavy resistance of the air and ground.
He gave me the phone number in order ______ contact him when we are in need of help.
You know that widely reading helps ______ your knowledge so I can’t help _____ the housework every day.
The factory is five kilometers ______ from his house.
The little boy found his toy you _____ under the bed.
The meeting ______ tomorrow afternoon is about _______ rid of pollution.