The outer layers of human skin are composed of dead cells impregnated with keratin and oil, which make the epidermis relatively impermeable to water, yet humans sweat freely in hot temperatures. This occurs because:
(A) the salt in sweat allows it to diffuse through the skin.
(B) sweat glands have special channels through the skin.
(C) an osmotic gradient in sweat moves it through the skin.
(D) sweating occurs in only those areas of the body where the skin is water permeable.

B) sweat glands have special channels through the skin

Explanation:

The human skin has special channels called the pores through which water and oil passes through. The pores are opening of the hair follicles on the skin.It serves as an important osmoregulatory method by the body. The sweat helps to cool off the skin when there is heat.

the correct answer is - d. china has a large and growing population.

the fact that china has a large (the biggest) population, and it is still growing, doesn't hinder the agriculture production in the country. in fact, it can for increased production in the agriculture, since there's more labor force, as well the sheer mass of people produces lots of scientists that come up with new inventions as to how to improve this sector. nice example is the inner mongolia region in china, in general dominated by the gobi desert, but few scientist came up with a nice idea as to how to make the region productive by using plants that are very resistant to droughts, so lots of people have been employed, and the region is becoming greener and greener each year, and the production of food in this region is also increasing.

photosynthesis makes the glucose that is used in cellular respiration to make atp. the glucose is then turned back into carbon dioxide, which is used in photosynthesis. while water is broken down to form oxygen during photosynthesis, in cellular respiration oxygen is combined with hydrogen to form water.