导致成品浓硝酸浓度低的原因是（）。
A.冷却水量大
B.浓硝酸量大
C.稀硝酸浓度高
D.回流酸量小
参考答案：D
What a low opinion she ___ of him! He doesn't think it much good ___ friends with her.[ ]
A. thinks, to make
B. has, making
C. thinks , making
D. has, to make
简析《寒夜》中曾树生的形象。
