题目

      It is said that about 60% of housewives have a brand         before entering the store. A. in mind                    B. on sale                    C. in possession         D. on purpose 答案：A新物种形成的标志是（ ）A.具有新的生理功能B.出现新的形态结构C.出现地理隔离D.形成生殖隔离