Https://www.theguardian.com/commentisfree/2013/jan/03/stravinsky-modernism-rite-spring-alarming
here is a link to a webpage talking about that
Luck on your work!
A supporting sentence is a sentence that supports the claim or reasoning with evidence
An independent variable is something in a conrolled experiement that is deliberately changed. A dependent variable is a variable that is changed based on the changes of the independent variable, it is dependent on the independent variable (if that makes any sense).
Hopefully I wasn't too confusing, hope this helps:)
In the phrase, the author used "like", symbolizing that she is using a simile to compare her memory to the fresh watercolour painting left out in the rain (which would surely end a disaster as the painting would mix with the rain and become destroyed), which helps the reader have a familiar comparison to how she is feeling. You could also say she uses imagery to help the reader visualize and understand her struggles of her horrible past.