题目

________, you need to give all you have and try your best．        A．Being a winner                     B．To be a winner                             C．Be a winner                         D．Having been a winner 答案：B在人的次级精母细胞（非后期）内，染色体的组成正确的一组是(    ) A．44＋XX    B．44＋XY     C．44＋YY    D．22＋X或22＋Y