What would happen if the sun disappeared, according to the passage?
A. Energy sources will run out.
Đáp án đúng là: D
What do teens feel when they study hard for an exam but get bad marks?
Based on the evidence in the passage, how can the sun be best described?
The Sun and the objects that travel around it is called ________________.
The word “pollutants” in paragraph 4 could best be replaced by “_________”.