题目

INTRODUCTION It’s hard to believe that I wroteNumber the Stars more than twenty years ago. It seems like yesterday that I answered the phone on a snowy January morning and received the news that it had won the 1990 Newbery Medal（美国纽伯瑞儿童文学奖） . I think readers of every age may match themselves with the important persons in the books they love and ask themselves: Would I have done that? What choice would I have made? And ten-the age of Annemarie inNumber the Stars —is an age when young people are beginning to develop a strong set of personal ethics（道德观 ; 价17．某生物兴趣小组观察了同种生物不同分裂时期的细胞，并根据观察结果绘制出甲、乙、丙三图．下列与图形有关的说法中正确的是（　　）A．甲图所示细胞处于有丝分裂后期，在此时期正发生同源染色体的分离B．乙图所示细胞可能处于减数第一次分裂后期，此阶段可能发生基因重组C．乙图所示细胞可能处于有丝分裂中期，此阶段染色体着丝点发生分裂D．如果丙图表示小鼠睾丸中分裂的几种细胞，则C组细胞所处的时期持续时间最长