B757飞机做45°坡度盘旋时其过载为：（）. ["1","1.2","l.4","2"]
无卸载装置的活塞式氟利昂压缩机，启动前的准备工作是（）。 ["启动冷凝器","检查曲轴箱油面","盘动联轴器","点动压缩机"]
B737飞机做60°坡度盘旋其过载为：（）. ["1","1.2","1.4","2"]
飞机重心位置对VMCA的影响为：（）. ["重心前移时VMCA增大","重心后移时VMCA增大","重心对VMCA无显著影响","重心后移时VMCA将减小"]
VMCA的意义在于，双发飞机在一发失效时只要不低于该速度就能：（）. ["保持住航向","保持住航向和高度","控制两翼水平","保持一定的爬升能力"]
简述古罗马政治制度的意义。
