请帮我看看这三句英文哪里能改改的,

题目

请帮我看看这三句英文哪里能改改的,
-For some underground workrooms which have no ventilators,air-conditioningequipments must be installed.
-In addition ,if the conditions permit,sports facilities are ideal for staffs to do exercise in the intervals of businese.
-these are done to protect the health of the workforce from hazards in the work environment
Secondly,reasonable timetableis also important for employee’s health.

答案

-For some underground workrooms ,which have no ventilators,air-conditioningequipments must be installed.which前加逗号,因为是非限定定语-In addition ,if the conditions permit,sports facilities are ideal...