The mantle. It is also the largest earth layer, making up about 84% of the earth.
Answer:
the answer is A
Explanation:
pH is a measure of how acidic/basic water
Guardrail systems must be capable of withstanding at least 200 pounds of force applied within 2 inches of the top edge, in any direction and at any point along the edge, and without causing the top edge of the guardrail to deflect downward to a height less than 39 inches above the walking/working level.
