A new study has found that social media could be affecting the sleep of young adults.

14. How did the researchers mainly carry out the study?
A. By doing online research.            
B. By doing questionnaires.
C. By collecting published data.        
D. By giving an example.
15.What can be inferred from the text?
A. Men are more likely to suffer from a sleep disorder than women.
B. People often using social media are less likely to have a sleep disorder.
C. Using computers less helps avoid sleep problems completely.
D. Sleep problems can be determined by the times of a person visiting social media.

答案12-15 :CBBD