Answer:
The correct answer would be - floor opening.
Explanation:
A floor opening is an opening or entry or hole that is at least 12 inches or more than that in the pavement, yard, platform, floor or anything in which someone or something can fall in it.
It is made for the entry or exit of person to fix anything under or above this pavement or platform. The best example of these floor openings is stair or ladder pit, manway hole, or hatchway.
Thus, the correct answer is opening - floor opening.
A. you need to use your maximum heart rate, which is determined by subtracting age from 220<span /> to set your intensity level.