In 1966 almost all of london burned down.为啥没be动词

因为此处burn是不及物动词,没有被动的形势,不需要be动词表示被动。burn不及物动词 vi。1。发热;发光The sun burns bright in the sky。太阳在天空明亮地照耀着。2。燃烧;着火Dry wood burns easily。干柴易燃。3。烧毁;烧焦;烫伤The factory burned to the ground。工厂被彻底烧毁了。4。发烧,发烫My cheeks burned。我的面颊发烫。5。(常用进行时)激动,发怒;热切盼望[(+with)][+to-v]We were burning with anger。我们十分气忿。6。快速行进[Q]7。晒黑及物动词 vt。1。烧毁The whole city was burned to the ground。整座城市都被烧光了。2。烧伤;烧坏;烧焦;烫伤The soup was so hot that it burned my mouth。这汤很热,以致烫伤了我的嘴。3。燃烧发出(热或光)4。(化学制品)腐蚀The worker's overalls were badly burned by acid。这位工人的工作装被酸腐蚀得很厉害。5。烧灼;烙6。使晒黑7。激起。。。的愤怒(或欲望等)8。消耗;浪费Our furnace burns oil。我们的暖气炉烧油。 再问： 此处是否+不+be动词都行 再答： 是 如：The building was burnt down。 房子烧毁了。