I’d appreciate         if you could turn the radio down. I’m doing my homework.

—What can I do for you?—I’d like to buy a computer for my son, ______ at a good price but of great quality．

(2013·高考安徽卷)This project requires close teamwork.________ will be achieved unless we work well together.

 —Please wait a moment. I have ____ to tell you.—OK!

Children find_____difficult to sit for hours with little to do while flying.