For the first red, you don't need an article before "relationship".
When you're saying "type of [word]", do not put any article before that word.
Example: "a type of device"
Not too sure about the "your back" parts. It could be your teacher does not like repition.
Also not too sure about "did". He probably wanted you to use the word "felt" instead of "did feel"
The first word of the last paragraph should be "in" not "at".
The red commas definitely do not need to be there.
Don't know why he marked "time to" and "to" red.
Answer:
- Disapproving of gossip and badmouthing, so the friend can feel uncomfortable and stop doing such harmful things
- Forming a study group/competing for better and higher grades
- Tutoring other students to share knowledge
- Encouragement to join different clubs with special interests (Debate, drama, computer science, etc...)
- Saving money to buy things/getting a job together.
Answer:
Sentence 1 is the correct answer.
