Use a process of elimination to answer the sentence completion questions. This involves looking at the meaning of the sentence, and in particular the words right around the missing word, and figuring out what kind of word should go there. Then eliminate those words with definitions that don’t line up with the sentence, and choose/guess among the answer choices left.
DO NOT eliminate words whose definition you don’t know very well. If you’re only vaguely sure of the definition for a particular answer, just leave it as a possible choice.
If you’ve got no idea what a word might mean, at least get a “feel” for whether it’s a positive or negative sounding word that you’re looking for. Then select among the positive- or negative-sounding answer choices.
SAT Prep Plan: SAT Tips 
