题目

 —Turn off the TV, Jack. ____your homework now? —Mum, just ten more minutes, please. A. Should you be doing          B. Shouldn't you be doing   C. Couldn't you be doing             D. Will you be doing 答案：B研究生物学的基本方法是（ ）A. 观察法和实验法 B. 调查法和分类法C. 观察法和归纳法 D. 调查法和实验法