题目

某学生在做“色素的提取和分离实验”时，收集到的滤液颜色呈现浅绿色。下列不会导致该现象出现的是 A．未加碳酸钙                                                B．叶片不新鲜 C．研磨不充分                                                D．无水乙醇加得太少What’s your best friend like?A. He is fine. Thank you. B. He is a doctor.C. He likes watching TV. D. He is helpful and generous.