当糖尿病患者出现增殖性视网膜病变时常伴有糖尿病肾病及神经病变。
参考答案：对
This is a _____ book that you may _____ in daily English study. [ ]
A. referring; refer to
B. referring; refer
C. reference; refer to
D. reference; refer
食品的浓缩
