题目

图中①和②表示某精原细胞中的一段DNA分子，分别位于一对同源染色体的两条非组妹染色体单体的相同位置上。下列相关叙述中，正确的是 A．①和②所在的染色体都来自父方      B．③和④的形成是由于染色体易位  C．③和④上的非等位基因可能会发生重新组合 D．③和④形成后，立即被平均分配到两个精细胞中Stephen Hawking, who is the most famous physicist, was born in Britain on January 8th, 1942. As a child, he was enthusiastic about 【1】 (design) complicated toys but 【2】 (fortune), in his twenties, he suffered 【3】 a disease that was impossible to be cured,【4】 was a great challenge for him. However, not only was he positive about the misfortunes, and eventually he 【5】 (defeat) all the obstacles but also he was 【6】 (absorb) in his research in the universe. In 1988, his best-seller A Brief History of Time 【7】 (publish), in which he put forward the idea 【8】 time itself has a beginning, and that it will have 【9】 end. In 【10】 (conclude), he has made outstanding contributions to the fields of cosmology and quantum gravity.