フリー問題

問題文

A copper smelter has a furnace line whose control gear has stood there for years and is covered by a rule of the works. Its risk office asks what the technical sort of standing condition is said to hang on. The smelter also has to settle how many things a plan for easing risk is said to mirror. Which pair fits what that sort of condition hangs on and the count of things such a plan mirrors?

選択肢

1. that sort of condition hangs on how the tool is used, and the things such a plan mirrors number 4.
2. that sort of condition hangs on how the tool is aged, and the things such a plan mirrors number 4.
3. that sort of condition hangs on how the tool is used, and the things such a plan mirrors number 3.
4. that sort of condition hangs on how the tool is aged, and the things such a plan mirrors number 3.