A:发生在生物体内的基因突变,有可能使种群的基因频率发生变化
B:两个种群间的生殖隔离一旦形成,这两个种群就属于两个物种
C:共同进化就是指不同物种之间在相互影响中不断进化和发展
D:物种大都是经过长期的地理隔离,最后出现生殖隔离而形成的
微博探讨
以下内容是摘抄自七年级中学生小雅的微博,请你结合所学知识为她排疑解难。
2010年10月1日18时59分57秒,搭载着嫦娥二号卫星的长征三号丙运载火箭在西昌卫星发射中心点火发射.经过5天的飞行和多次的近月制动,它于10月9日进入极月圆轨道,卫星绕月球飞行一圈时间为117分钟.则下列说法正确的是( )
阅读理解。
Aunt Judy's birthday is coming. She will be 38 years old. Dad and Mum are going to take me to her house. She lives in Guangzhou. We are going to go there by train. Her birthday party will be on Saturday. We are leaving on Friday afternoon. And we are coming back on Sunday evening. I am going to give my dear Aunt Judy a picture . I am drawing it now. I am drawing some beautiful flowers. I am drawing a small dog, too. That's because she likes dogs. The picture will be very nice.