Errors on the hard disk on your Mac OS X computer can be the cause why the computer doesn't run as fast as it used to. Let me show you how to check and repair the errors on a disk drive.
Science is a systematic enterprise that builds and organizes knowledge on diferent branches. In this knowledge check we have prepared for you a few general knowledge questions of science.
SQL is a standardized query language for requesting information from a database. You can verify your knowledge by trying to answer a few simple questions.
