Answer:
.
Explanation:
To explain the last sentence, what I mean by that is the sudden decrease in air pollution in just a few weeks is what would have typically taken multiple years to do. Due to less drivers, factories shutting down, and more, less toxic and infirm mental hazardous chemicals were released into the atmosphere in an extremely short amount of time. However, nowdays, it is almost back to where is was before the pandemic.
Transport
The protein is working to transport substances across the membrane.
I think BO or B, but BO has more chance.
