Write a paragraph explaining the steps involved in a muscle contraction starting from the brain sending a signal to the muscle and ending with the muscle contraction.

what are the options

they had the law tat factories that produces smoke cannot be built near residential buildings.

building of proper sewage system was done to ensure that the waste is carried away from the humans so that they do not get diseases from it.

also they built water systems to provide water in those areas which are drought prone.

bal is blood alcohol level. bac will normally be higher in a person with more body fat. so the answer to your question would be, as body fat decreases, the increasing rate of bal decreases.  

its b. greenhouse gasses trap uv rays for heat so that the plants stay alive.