The first sentence is an interrogatory question, so a question mark is used. The second sentence is a declarative sentence and will use a period. The third sentence is an exclamatory sentence, and should use an exclamation mark at the end.
Answer:
Thomas is still feeling depressed, because everyone was informed about his low marks/grades.
Explanation:
Acheivement is only positive. You cannot write 'low acheivement'. Hope this helps.
What do you want to ask, if you cannot understand, please ask me, I am a Chinese girl