题目

(2019·湖南岳阳质检)玉米是一年生雌雄同株异花受粉植物，其子粒的颜色受两对等位基因A、a和B、b控制。A基因存在时，能合成酶Ⅰ；B基因存在时，酶Ⅱ的合成受到抑制，两对等位基因独立遗传。子粒颜色的转化关系为： 白色黄色紫色 研究发现纯合紫粒玉米的花粉完全败育，不具备受精能力，其他类型玉米的花粉正常。将杂合白粒玉米和纯合紫粒玉米进行间行种植，F1中收获得到的玉米共有三种类型：白粒、黄粒和紫粒。请回答下列问题： (1)上述实听下面一段较长对话， 回答1-3小题。1. What does the boy do to practice his spoken English?A.He just read aloud every morning .B.He often talks to his teacher and classmates in English.C.He often goes to English corners.(英语角)2. What does the boy think of his English?A. very goodB. very poorC. He doesn’t know3. Where is the English corner ?A. in the libraryB. in the classroomC. in front of the library