Which valves control the exit of blood from the heart’s ventricles into the arteries?

The brain is part of the nervous system.

Which system contains layers such as the epidermis and dermis?

please upload pictures of your work.  If you didn’t draw a question on paint you can upload a separate picture or just submit “see work”  and make sure your work is labeled… 

It is advantageous to make the bench face angle as steep as possible. Why? 

What is not an advantage of continuous mining methods?

Define the following mining terms: Drift Raise

Why is the concept of net present value important to mine planning?

This mining method is used for deep deposits when traditional underground mining methods are uneconomical.  Water, acid and steam are pumped down holes to extract the ore.

Name the mining method most likely to be used, given the information provided (answer two of the three questions) A 60’ thick bed of salt, flat lying, and under 2500’ of competent overburden. A 5’ thick flat-lying coal seam that has outcropped on the side of a mountain in West Virginia. A very high-grade gold deposit occurring in narrow and sinuous veins, starting at a few hundred feet below the surface and plunging to great depths. The host rock and ore are weak.