Before allowing an employee to enter an excavation at least four feet deep in must be tested for oxygen deficiency and toxic fumes. true or false

The given statement is true.

Explanation:

As one goes deeper to the ground, there would be less availability of air and space for the air to come in. This signifies that the concentration of oxygen on the lower section of the excavation seems to be less in comparison to the upper ground. The deeper ground would also seem to comprise gas and oil that got developed by the millions of years’ procedure. These resources seem to be dangerous and toxic to get close by without gearing protective masks.

201cm/s÷5: 18

explanation:

there is no explanation

geosphere and hydrosphere.

this is because the geosphere has to do with geological events, while the hydrosphere controls all water on earth.