I found him _________ in an armchair, ___________.
You must ______ a wide vocabulary if you want to learn a language well.
Don’t bother Tom, he is ______ with the experiment on water molecules in the lab.
Nowadays some parents regret not ______ more time with their kids when they were young.
Have you heard that he, as well as his parents, ______ visited the Summer Palace? —Really? No ______ he didn’t attend the meeting.
Only ______ a human being.