题目

用吸管从草履虫培养液中吸取草履虫的最好部位是 ( ) A．培养液的表层B．培养液的下层 C．培养液的中层   D．培养液的任何部位 答案：A. ---Goodbye, Peter, remember me to your parents. ---_______. A. It’s very kind of you to say so.              B. Thanks, I will. C. You are so kind.                         D. Thanks, what a good idea.