I had not seen him for years,but I_________ his voice on the phone.

There is _______ “s” and _______ “u” in the word “study”.

It is uncertain side effect the medicine will bring ?about?,although about two thousand patients have taken it. [ ]

30. unemployment rises．

I’d like to call you at 10 o’clock nextFriday morning if it is convenient.—I’m afraid I _______ an important meeting.