dmz区域(非军事化区)的安全级别中等，因为需要对外开放某些特定的服务和应用，受一定的保护，是安全级别较低的区域。()
ieee最初制定的无线局域网标准是ieee802.1。()
The word "unwarranted"(line 3, para. 2)most probably means "______".
A. undeserved
B. unnecessary
C. extreme
D. unfair
Which of the following titles is most appropriate to the text？
A. The Failed Search for an Earthquake Prediction System
B. The Merits of Trying to Predict Earthquakes
C. The Debate over Earthquake Prediction Systems
D. The Drawbacks of Earthquake Prediction Systems
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