What can young people practice on the Internet？They can practice（）by talking with people.
The causes of sleep problems in older people remain unidentified.（）
A. Right
B. Wrong
C. Not mentioned
Sleep problems can seriously affect one’s quality of life.（）
A. Right
B. Wrong
C. Not mentioned
Clinical depression is different from （）.
A. a character flaw
B. normal sadness and grief
C. a definite possibility
D. dependency and disability
E. a significant risk factor
F. unrecognized and untreated depression
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