being是be的现在分词形式，用于被动语态的进行时(或进行时的被动语态)。比如she is always being criticized她总是处于被批评的状态，be criticized 被批评，be being critized 正在被批评
being在现在时中通常用于系动词之后,而句子通常是被动语态.
被动语态的句子通常是物做主语+系动词+动词过去式.当被动语态的句子表示现在时的时候,就必须在系动词后面加多一个being
例如楼上那个人说的句子,我做一些修改.The building is being built for living.这个句子如果是现在时态.如果只是一般的被动语态,那么句子将变成The building was built for living.
明白现在时的用法了吗?
所以,如果把楼上的另外一个题的现在时改一下,变成过去式,应该是The traffic accident was invested by the police
