题目

 — So much work needs to be finished in such a short time. — _________  I’ll give you a hand. A. Not to worry.                      B. So what? C. You can’t be too careful!      D. That’s right. 答案：A正常男性体细胞的染色体组成是（　　）A．23对+XB．23对+YC．22对+XXD．22对+XY