It could be about various science concepts like the life cycle of organisms, basic physics principles, or the study of ecosystems. Since it's for seventh grade, it might cover topics that are introduced at that level in the curriculum.
Terrified means to describe extreme panic and fear, causing people to feel extremely shocked and terrified. Calmness meant that one's thoughts or spirit were calm without uneasiness or suppressed feelings. One had suppressed or re-restrained one's feelings and calmed down.
I'm not entirely sure without more context. It could have features like being designed for seventh - graders to practice reading skills, perhaps with various story genres.
The word 'smoky' meant that the entire area was shrouded in smoke, making it a blurry state. Her fingers were blurry, and her eyes were covered in smoke.
Lan meant big waves. In Chinese,"Lan" was often used to describe the ripples of water, such as the raging waves to describe the surging waves, and "Qing Lan" to describe the ripples on the clear water surface. In addition,'Lan' could also be used to describe the fluctuations of other things. For example,'Xin Lan' could describe the fluctuations in one's heart, and 'Lan Yang' could describe the ups and downs of one's thoughts. Lan could also be used as a metaphor. For example, Lan Man described the continuous expansion and spread of things, and Lan Qi described the rise and emergence of things.
The word " dark " was used to describe a very dark state. There was no light, and it was pitch-black. It could be used to describe a night without stars, or it could also refer to the very dark appearance of a house or cave, which made people feel afraid. For example, he got up when the sky was still dark.
Lan meant the fence or railing in front of the door. It could be used to refer to railings or rings. In ancient poems, the night was the time when the night was quiet and the night was about to end. It could also mean to block or to end.