交换器中树脂流失的原因有哪些？
参考答案：
（1）排水装置损坏，如排水帽脱落或破裂、石英砂垫层乱导或塑料网套损坏等；（2）反洗强度过大反洗操作不当。
________ on the small island, the tower has been seriously damaged by the sea water?[ ]
A. Being lain
B. Lain
C. Being located
D. Located
药用部位为子实体的是（）
A、海藻
B、冬虫夏草
C、灵芝
D、茯苓
E、松萝
