He always dreams of ______ a chance for him to go abroad for further study．

－How much shall I pay for the phone call?－You __________. This is free of charge.

ys, scientists are working hard tofind a best way of treating addictions __________ drugs

The work is too hard, so ____ were needed.

I used to _____ a lot, but now I have become fatter, for I mainly stay at home watching TV.