题目

阅读理解 Mr. Black was a farmer. He lived alone by the forest. He had no daughters or sons. He planted rice and vegetables. Also, he sometimes caught small animals for food. So he kept two dogs to help him. One dog was big and the other was small. He liked them very much. One day, his friend Mr. Smith, another farmer, came to visit him. Mr. Black was very happy. They haven’t seen each other for about three years. When the friend saw two holes(洞) in the door, a big hole and a small hole, he was surprised and said, “My dear friend, why are there two holes in your door?” “Let六月，正是我市桃子成熟上市的时节．在你享受桃子的甘甜之时，是否知道桃树是怎样开花结实的呢？请据图回答下列问题．（1）“人间四月芳菲尽，山寺桃花始盛开”．这句诗反映出，影响桃树开花的非生物因素是________．（2）要观察桃花子房里面的胚珠，应采用的方法是________A．用刀片横向剖开子房，用显微镜观察B．用刀片横向剖开子房，用放大镜观察C．用刀片纵向剖开子房，用放大镜观察D．用刀片纵向剖开子房，用显微镜观察（3）桃花是虫媒花．蜜蜂等昆虫将花粉从[________]________传到雌蕊的柱头上的过程，叫做传粉．（4）桃花花粉管里的精子进入胚珠，与卵细胞结合形成受精卵．这说明，桃可以进行________生殖．（5）桃花凋谢以后，在花着生的位置会出现小小的桃子．甘甜的桃肉是由[________]________发育来的；桃子里面的桃仁是由[________]________发育来的．