I used to feel very nervous when I stood up in front of others, but now I feel quite ______when giving a speech to the school.
Studies show that sunshine, fresh air, and plenty of rest often _______ a person’s recovery from sickness.
He has little acquaintance _______ music , while he has a wide knowledge ____ painting.
He insisted what he did _______ right and that anyone who broke laws ________.
It’s uncertain _______ side effect the medicine will bring about , although about two thousand patients have taken it .
--Sorry, I have to _________ now. It is time for class. --- OK, I’ll call back later.