well if she has 15 now then you add 3 to 2 which is 5 then add that to the 15 so you get 20 in total then minus th3 6 she made today you get 14 divided by 2 which is 7 she made 7 yesterday and 13 today which is 20 so the answer is 7
Answer:
The troposphere
Explanation:
It begins at the surface of the earth and extends out.
The second one is A, amount of time
<span>The
higher the altitude, the lower the atmospheric pressure. Lower pressure
in turn causes water to evaporate more quickly, and water actually
boils at a lower temperature. The percentage of oxygen in the air at two
miles (3.2 km.) is the same as at sea level (21%). However, the air
pressure is 30% lower at the higher altitude due to the fact that the
atmosphere is less dense--that is, the air molecules are farther apart.
The important effect of this decrease in pressure is this: in a given
volume of air, there are fewer molecules present. This is really just
another way of saying that the pressure is lower. This is called Boyle's
law.</span>
