If you want to see a doctor, fix the date with him ahead of time. This is a common ___________ in the USA.A. habit B. law C. rule D. custom
He speaks English well indeed, but of course not _____ a native speaker.
Computers have been made ______ clever that they can ______ problems like humans _______.
Old people need special care in winter, as they are very______ to sudden change of the weather.
--- Let’s go to play football, shall we? --- Sorry, I can’t. I must go over the points the teacher explained ______ I forget them.
You may not understand what they have done, because they ____ a younger generation.