________ enough time, but he couldn’t do it better. 

We leave it to your judgment ____ you should do it.

Disappointed, I was about to leave ____ something occurred, which ____ my attention.

Now there is just one point   I wish you to make clear.

22．Lawrence Craven, a doctor from the USA，is the author of several published reports, one of______ introduced the idea in 1953 ______aspirin could reduce the risk of heart attacks．