题目

My classes finish _________ 3:00 p.m. every day. After that, I play soccer with my friends _________ an hour. A . at; to B . in; for C . at; for D . in; to 答案：C“龙生龙，凤生凤，老鼠的儿子会打洞”这句谚语说明的生物现象是（ ）A．生殖B．发育C．遗传D．变异