题目

_______the days ______ I spent with Jane on the farm, I still can't figure out what went wrong. A . Looking forward to; when B . Looking back on; that C . Looking into; which D . Looking back on; when 答案：B下列关于染色体和基因的叙述中，错误的是（　　）A．基因位于染色体上B．基因是决定生物性状的最小单位C．人的体细胞内的染色体成对存在D．细胞内所有染色体的形态和功能均相同