How does the author support her argument that sleep is important to good health? a. by describing the different states of sleep
b. by describing ways to the reader get enough sleep
c. by describing the consequences of inadequate sleep
d. by deacribing the importance of diet and exercise

the italian poet francesco petrarch did! (:

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.