I am recently reading the articles "Search for squarks and gluinos using final states with jets and missing transverse momentum with the ATLAS detector in sqrt s=7 TeV proton-proton collisions". However, as my limited knowledge, many technical terms that I am understanding as a result I am now struggling with it. By the way, I am second year undergraduate. I will so appreciate if someone can help me to explain the following: -what is the purpose of 'control region' and 'signal region'? e.g QCD control region. -true/fake missing transverse energy. -Monte Carlo simulation, I often came across the term' QCD Monte Carlo'. -reversed delta phi cut. -(jet)response function. -seed events, smearing. eg. smeared the seed events.(really need explain for this) -(jet)triggers. -pseudo-data -pt balance -and finally, 'cut' etmiss cut, pt leading jet cut, etc.... I am not very good in English. Hope someone can help me, Thankssss!