生产、储存和装卸易燃易爆危险物品的工厂、仓库和专用车站、码头,必须设置在城市的边缘或者相对独立的安全地带。()(易)
参考答案:对
已知锐角△ABC的内角A,B,C的对边分别为a,b,c,且23cos2A+cos 2A=0,a=7,c=6,则b=________.
A
School Watch can help its members ______.
A.save the environment
B.organize sports activities
C.improve the quality of school life
D.do home work