聚磷酸盐所形成的保护膜属于()。
A.氧化膜
B.吸附膜
C.沉淀膜
参考答案:C
Some rules are almost the same _______ in the world, but rules of etiquette can be different from place to place. [ ]
A. somewhere
B. anywhere
C. nowhere
D. everywhere
慢性泪囊炎对眼球构成潜在威胁是由于()
A.泪道探通损伤角膜
B.沙眼
C.可继发白内障
D.分泌物有大量细菌
E.泪溢