制备微球可生物降解的材料()。
A.聚维酮
B.氰基丙烯酸异丁酯
C.聚乳酸
D.磷脂
E.醋酸纤维素
参考答案:C
解析:
[知识点] 靶向制剂
Although the Eiffel Tower ________ to last for 20 years, it is still standing today.
A.has designed
B.had designed
C.is designed
D.was designed
简述过烧缺陷的特征。