The ages of the winners of a cycling tournament are approximately bell-shaped. the mean age is

The mean age is, approximately, 28.6 years.

Explanation:

Cycling is a sport practiced with a bicycle. The practitioner of this sport is called a cyclist. In a cycling competition, the goal of the runner is to complete the race course before the other competitors, many compete professionally. Cycling requires good physical fitness which is an exercise that greatly stimulates various muscles. Although there is no age when cycling is prohibited, the average age of tournament champions has been approximately 28.6 years.

i'm thinking (a) to keep sand in place; ////////////

explanation: a sand fence or sandbreak, like a snow fence, is used to force windblown, drifting sand to accumulate in a desired place. sand fences are employed to control erosion, sand dune stabilization, keep sand off roadways, and to recruit new material in desert areas.

it has to be understood that the sea water contains a huge amount of sodium and chlorine ions and if they enter the cell of the atlantic cod fish, the cell will shrivel and the fish will die. to avoid such a condition, the fish uses active transport for the purpose of removing the ions against the gradient.

explanation:

the atlantic cod is not a maritime osmoconformer. its native application of salts is less than that of the seawater it lives in. it is continually falling water from the gills to the ocean via osmosis.

countering that, the fish is going to be swallowing seawater. but since its internal collection of salts is lower than seawater, the fish will want to go free of excess salt, and since that's going upon a gradient, then active transport, requiring energy, must be used to pump out the salt. much marine fish use the organs to filter out the salt and these fish discharge very straight urine.