题目

——Why was there no reply when I rang you at ten this morning? ——Because I___ in the supermarket. A. was shopping       B. had shopped     C. shopped            D. did shopping 答案：A在有丝分裂中，DNA复制发生在   Ａ．中期　　　　    Ｂ．后期　　　　    Ｃ．间期　　　　    Ｄ．前期