Good news! We'll have ____ one-day holiday in order to celebrate the 70th annzversary(纪念日)of the victory in World War II.
计算:﹣22+(12)﹣1+(1-tan60°)2= ____
如图,DE∥BC,EF∥AB,且S△ADE=4,S△EFC=9,则△ABC的面积为____。