"In our minds we tried to pin her to a corkboard like a butterfly,
but the pin merely went through and away she flew."
What is the author's purpose in including this simile about Stargirl?
A. The simile portrays how often the other students are surprised by Stargirl.
B. The simile portrays that Leo is madly in love with Stargirl.
C. The simile portrays the crowd's reaction to Stargirl at the football game.
D. The simile portrays Stargirl's obsession with taxideimy.

C

Explanation:

The author's purpose to include this simile about stargirl was to illustrate how stargirl changed dramatically throughout the story and how the crowd saw her amazing performance during the football game.

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.