What is a secure chemical landfill?

a. a landfill that is completely full and closed

b. a landfill in an area of nonporous bedrock

c. a biological treatment plant for liquid waste

d. a guarded, fenced, and locked landfill

I would say B.

Because nonporous means it cannot absorb liquids or gases. That is exactly what we want. If the gases and liquids seeped through, it would mix with our water making it unsafe.

many other transport proteins, often called pumps, move materials against a concentration gradient. active transport drives molecules across a membrane from a region of lower concentration to a region of higher concentration. this process, shown in figure 5.1, uses transport proteins powered by chemi- cal energy.