【判断题】钢板探伤时,超声波的频率多为1.5M~5MHz ,在房间中利用空气探头进行超声防盗时,超声波的频率多为35k~45kHz。
【单选题】What is the main idea of the passage?
A.
Loneliness can spread.
B.
Loneliness is linked to depression.
C.
Lonely people tend to grow fat.
D.
Lonely people need more friends.
【单选题】What is the best title for the passage?
A.
Three Kinds of Loneliness.
B.
Loneliness and Diseases.
C.
Loneliness and Social Contacts.
【单选题】Suffers of loneliness mm to suicide as a final solution to their loneliness.