What do you want to be when you _______ —–An astronaut.

______plastic bags we use, _____it will be to the environment.—-I agree ____you .

No sooner _____ a paper on his latest research than he was asked to write another for the program.

Lu Xun is known notonly a great writer but also a great thinker.

We all know the truth _____ there are air, water and sunlight there are living things