Explain how you can use mental. math to perform the following addition

You can use mental math to perform the following addition by knowing that certain numbers equal a certain number. for instance, you know that 9+2 is equal to 11. you don't need a calculator to solve that. then you know that 1+8 is equal to 9.since you are adding 11 you know that the answer is 19. you can use that to answer to following equation. 

A. Fungi are used to make bread.

C. Fungi can cause diseases in plants.

D. Fungi can cause diseases in humans.

F. Fungi are used in the development of antibiotics.

Explanation: HOPES THIS HELPS