Answer:
London smog results from a high concentration of sulfur oxides in the air and is caused by the use of sulfur-bearing fossil fuels, particularly coal. This type of smog is aggravated by dampness and a high concentration of delayed particulate matter in the air.
Explanation:
So, the answer would be B or D.
But, it is most likely B due to dampness.
So you can make the world greener
Active transport requires energy when moving molecules against a concentration agent. It requires for specific membrane transport proteins. Only a certain type of protein can move a certain type of substance.
The three main types of Active Transport are:
1) Sodium-Potassium Pump
2) Endocytosis
<span>3) Exocytosis </span>
The difference in an area with high concentration and an area with low concentration is called concentration gradient.
<h3>What is concentration gradient?</h3>
Concentration gradient refers to the difference between the concentrations of two solutes in a solution.
A solution usually contains an area or region with higher concentration and an area with lower concentration.
The difference between these two areas of different concentrations is referred to as a concentration gradient.
Learn more about concentration gradient at: brainly.com/question/13050811
#SPJ1