It’s uncertain _______ side effect the medicine will bring about , although about two thousand patients have taken it .
The naughty boys would play _________trick on _________ neighbors who didn’t give them any sweets on Halloween..
If you cheat in the exam, you can hardly _________it.
—Would you mind if I turned on the radio and listened to some music?—_________. In fact, I also like listening to music.
A friend is like a mirror. When you stand in front of a true friend, what is ____back to you?
In the cafeteria, I saw my sister and her three friends, none of ____ I had ever seen before.