We are wondering ________ we canprevent people from polluting the earth.

al evidence began to__________, suggesting that thenew drugs had a wider range of useful activities than had been predicted fromexperiments in animals.

Is it Jim who is driving the new car? —Probably. I know he has recently bought a ______ car.

Tony is ______ lazy, and he is not good at learning English.

Mr. White told us _______ run up and down the hall.