Fear can be an effective way to change behavior. One study compared the effects of high-fear and low-fear appeals on changes in attitudes and behaviors related to dental hygiene (卫生). One group of subjects was shown awful pictures of （1） teeth and diseased gums; another group was shown less frightening materials such as plastic teeth, charts, and graphs. Subjects who saw the frightening materials reported more anxiety and a greater （2） to change the way they took care of their teeth than the low-fear group did.
　　But were these reactions actually （3） into better dental hygiene practices? To answer this important question, subjects were called back to the laboratory on two （4） (five days and six weeks after the experiment). They chewed disclosing wafers (牙疾诊断片) that give a red stain to any uncleaned areas of the teeth and thus provided a direct （5） of how well they were really taking care of their teeth. The result showed that the high-fear appeal did actually result in greater and more（6） changes in dental hygiene. That is, the subjects （7） to high-fear warnings brushed their teeth more （8） than did those who saw low-fear warnings.
　　However, to be an effective persuasive device it is very important that the message not be too frightening and that people be given（9） guidelines to help them to reduce the cause of the fear. If this isn't done, they may reduce their anxiety by denying the message or the （10）of the communicator. If that happens, it is unlikely that either attitude or behavior chan~e will occur.
A．accustomed 
B．carefully 
C．cautiously 
D．concrete 
E．credibility
F．decayed 
G．desire 
H．dimensions 
I．eligible 
J．exposed
K．indication 
L．occasions 
M．permanent 
N．sensitivity 
O．translated