An author would include subheadings in an article to. 1.)include interesting formatting
2.)break up the article so it’s not too long
3.)help a reader skim the information
4.)highlight data and statistics

4 d

Explanation:

the reason is because they need to high light the important thing

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.

eager to consume a lot of food? insatiable appetite?

explanation: