单项选择题
You must believe that all your efforts taken for the project will （）.
A.pay upB.pay overC.pay offD.pay out
单项选择题 The ads are intended to improve the company’s( ) .
单项选择题 I’m feeling a little depressed at the moment，but I’m sure good times are （）.
单项选择题 The rate of population growth reached a peak in 1999 and declined in ( ) years.
