could any one help me to get 100% accuracy in critical reasoning ,though i have no problem with sentence correction and little problem with rc i have scheduled my gmat on may 14 2012,so i have little time to improve .
You have a month to improve critical reasoning. It is plenty of time to improve on breaking down the conclusions vs. the premises if you've had trouble doing that. I'm not a super GMAT whiz, but my goal in taking the test is to make sure I get the average difficulty questions all right so I can get to harder difficulty questions and get about half of the hardest questions right. That's the way the GMAT works.
Getting 100% of your critical reasoning questions right is almost impossible on the GMAT. Even someone with a 50 or 51 in Verbal will probably not get every question right.