He was a(n) ___________singer until the age of 40, when he turned professional.
_____the 19th-century America, the novel Gone with the Wind tells the story of a woman facing war and starvation bravely.
You did me a huge favor. However, I lack words_________to express my thanks.
Tom was running out of time in the exam, but there still remained several questions_________. A. to be answered B. to answerC. answered D answering
If you need any more paper, I'll bring you_________.
An economist is____________expert who will know tomorrow why_________things he predicted yesterday didn't happen.