Another Metro emergency preparedness exercise to keep in mind: later this week, the Friendship Heights Metro station will host a training drill that simulates a report of gunfire in the station. The mock shooting will involve two shooters and multiple casualties. According to the D.C. Homeland Security & Emergency Management Agency, the exercise is scheduled for 12:30 a.m., after closing, on Thursday, Feb. 25, so it won’t interrupt Red Line service. It will, however, bring…