The moods described above are a reflection of a person's emotions. Judging from the context of the story, we can deduce the remarks made by the characters. For example, a sigh is a deep release of breath expressing sadness, tiredness, etc. Given that his teacher had just scolded him we can conclude that Weiqiang sighed when he arrived at the canteen. Also, seeing that Ms. Lim was angry with her student, we can conclude that she snapped, that is; used an irritable tone when telling Weiqiang to study hard.
Option 1. It keeps the audience engaged in the plot by suggesting more potential conflict in the story. (This is only one I could get theres more but I cant find. If its wrong comment on my profile I will give points bye asking a random question)
