QUESTION 1 (POLL) Straighten your arm away from you, and then bend it back
towards you. What is happening with your arm muscles? Check
all that apply.

They contract and relax.

They move my bones.

They get shorter and longer with each
movement.

They stay the same.

The rock in a lead ore deposit contains 89 % pbs by mass. how many kilograms of the rock must be processed to obtain 1.5 kg of pb?

What forms when chemical reactions combine pollution with sunlight?

Miner's coal distributors does not mine coal itself, nor does it even store or handle the coal. instead, miner's solicits orders for low sulfur coal from other firms, then purchases the required amount from suppliers and directs them to ship the coal to its customers. what is miner's