带电作业工具室内应清洁干燥，相对湿度应保持在50%以下。
参考答案：错
解析：原题中50%以下，应改为：50%～70%
The new librarian still doesn't know ______ the out of date newspapers and magazines.
A．what to deal with B．how to deal withC．how to do with D．what to do away with
早期釉质龋病变在哪一层病损区范围最大（）
A.透明层
B.不透明区
C.表层
D.暗层
E.病损体部
