As is known to all language learners, newly learnt words will soon be forgotten unless ______ used in everyday communication.
It ______ to me that I might try this way to deal with this problem.
—The tree is so tall. —Yes. It ______nearly 20 metres.
Most of the Europeans refuse to accept GM food ______Americans regard it as the fruit from high tech.
Not only John and Tom but also their sister, Mary, ______great interest in the piano lessons.
—Shall I wait here for three hours? —Yes. Three hours ______for you to wait for such a doctor.