Tom is very sleepy.________ , he is still doing his homework.

Emma Watson hid free books around London underground to encourage people_ the habit of reading on the subway.

Not only _____ polluted, but _____ crowded.

ists are tryingto develop a special material, ________ they will make use of in spacecraft.

______ a man knows what is not to be done, will he succeed in doing what is to be done.