If he had really pulled the trigger, I would have __________ then and there.
已知向量a→=(1,2),b→=(1,0),c→=(3,4),若λ为实数,(b→+λa→)⊥c→,则λ的值为____
某中学地理兴趣小组拟绘制一幅校园平面图.实际测得教学偻与图书馆间的距离为300米,如绘到图上的距离为30厘米,则同学们采用的比例尺应为( )