(3) According to what you said, there are countless points M. For any point Q on OB, we can make such a straight line: first pass through Q as the vertical line of OB, and then make the middle vertical line of QC. The intersection of two straight lines is naturally the point m (obviously, the angle MQB of MC=MQ is 90 degrees, that is to say, for each point Q, at least the point M that meets the conditions can be found.
A. What conditions do special post teachers need to have to apply for the exam?
Junior high school: (1) Education: Bachel