单项选择题
M: May I see Professor Kent, please W: I’m sorry, he has been ill since last Friday. He will be back next Thursday.
A. Next Tuesday. B. Next Thursday. C. Next Wednesday. D. Next Friday.
A. The Cosmic Ocean B. Sunbeams C. The Speed of Light D. Random Numbers
A. To bring attention to the needs of the elderly. B. To contrast birth rates and life expectancy rates. C. To explain how and why the American population is aging. D. To show the percentages of age groups in general population.