在带压不置换焊补中，容器及管道必须连续保持稳定负压，这是动火安全的关键。()
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工件接触面有污垢会增大电阻，使电阻焊时产生更多热量，对焊接有利。()
According to Paragraph 3, informants among the American federal employees_____.
A. disclose misbehavior. externally when they are disappointed internally
B. get more protection than people who disclose misbehavior. externally
C. have less rights than prisoners
D. get as much protection as before
The word "snooping" (Para. 5) most probably means _____.
A. scrambling
B. mquiring
C. invading
D. researching
秦时创制三公九卿制，九卿包括：奉常、郎中令、卫尉、太仆、廷尉、典客、宗正、治粟内史和少府，九卿是具体掌管祭祀、礼仪、军事、行政、司法、文化教育、事务之官。()
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