What is one way mangrove forests directly benefit people? A)
They provide a habitat for reptiles.

B)
They act as barriers against floodwaters.

C)
Multiple layers of life live in and around them.

D)
Tree leaves and roots filter out salt from ocean water.

B

Explanation:

The large, thick trees and surrounding habitat of the mangrove forests are perfect for blocking storm surge, and tropical storms. It makes the most sense to choose (B).

same test same problem

the present continuous is a verb tense which is mainly used to indicates that an action is in progress at the moment of speaking.  

it is formed using: person + verb to be (am/is/are) +verb + - ing form  

example: i am studying at this moment .

in addition, the present continuous is also used in order to express things that will or will not happen in the near future.

example: i am having dinner with some friends tonight.

the speaker sometimes   uses it   to express that an action is repeated and it causes irritation on the part of the speaker

example: my sister is constantly complaining about everything.