I think it's the culture/genes they were brought/born into. Because it can be genetically made into your DNA or you might be raised in that certain household/culture that you're used to.
Bring it up to ur instructor, and if hes not willing to do anything file a formal complaint at your college.
Answer:
If there has to be one, it should probably go after the word "said"
Explanation:
"Amber said, I hope I am not late for the school bus this morning."
I would say that it doesn't really need a comma, but if it <em>has </em>to have one then that would be the most logical answer.
Answer:
放学后，他去图书馆看书。Without the comma, it would be 他放学后去图书馆看书。
Explanation:
The literal translation of the first one: After school, he goes to the library to read books. The second one is: He after school goes to the library to read books. 放学=after school 后=after 他=he 去=go/goes 图书馆=library 看=see (in this case "read") 书=books
