Answer:
the troposphere directs the light towards us.
<u>Answer:</u>
<em>
heat is released by the combustion of 
of methane</em>
<u>Explanation:</u>
The value of enthalpy determines whether the reaction is exothermic or endothermic. If the enthalpy change is positive, then the reaction is endothermic (heat or energy released) and if the enthalpy change is negative then the reaction is exothermic (heat or energy absorbed).
![\Delta H \ reaction=[ 2(\Delta HfCO_2)+ 4(\Delta HfH_2O)]-[2(\Delta HfCH_4)+4(\Delta HfO_2)]](https://tex.z-dn.net/?f=%5CDelta%20H%20%5C%20reaction%3D%5B%202%28%5CDelta%20HfCO_2%29%2B%204%28%5CDelta%20HfH_2O%29%5D-%5B2%28%5CDelta%20HfCH_4%29%2B4%28%5CDelta%20HfO_2%29%5D)
=![2 ( -(393.5 KJ)/mol)-[2( -74.6 KJ/mol)+4(-241.82 KJ/mol)]](https://tex.z-dn.net/?f=2%20%28%20-%28393.5%20KJ%29%2Fmol%29-%5B2%28%20-74.6%20KJ%2Fmol%29%2B4%28-241.82%20KJ%2Fmol%29%5D)
![= -787 KJ/mol-[ -149.2 KJ/mol-967.28 KJ/mol]](https://tex.z-dn.net/?f=%3D%20-787%20KJ%2Fmol-%5B%20-149.2%20KJ%2Fmol-967.28%20KJ%2Fmol%5D)
<em>In this question, </em><em>the enthalpy of formation</em><em> has positive value and hence the </em><em>reaction is endothermic</em><em> in which the heat is released.
</em>
Answer:
A The mating of two particular sheep to produce thicker wool
Explanation:
Selective breeding, also known as artificial selection, is the process in which people will choose two parent organisms to breed and create offspring with desired characteristics. In this case we want the sheep to breed and produce thicker wool.
Depression that repeatedly occurs with the onset of autumn and winter is to seasonal affective disorder as chronic, low -grade depression is to dysthymic disorder. Seasonal affective disorder is a type of depression that is related to changes in seasons such that it begins and ends at about the same times every year. Dysthymic disorder is a smoldering mood disturbance characterized by a long duration as well as transient periods of normal blood.
A common resource (or the "commons") is any scarce resource, such as water or pasture, that provides users with tangible benefits but which nobody in particular owns or has exclusive claim to. A major concern with common resources is overuse, especially when there are poor social-management systems in place to protect the core resource.
