There are a lot of changes happened around us对么?happen是不及物动词啊,怎么能加ed呢?如果是过去时也是前面的be动词变化啊,我不懂了……请大家解答一下呢……

There are a lot of changes happened around us对么?happen是不及物动词啊,怎么能加ed呢?如果是过去时也是前面的be动词变化啊,我不懂了……请大家解答一下呢……
There are a lot of changes happened around us对么?
happen是不及物动词啊,怎么能加ed呢?如果是过去时也是前面的be动词变化啊,我不懂了……请大家解答一下呢……

There are a lot of changes happened around us对么?happen是不及物动词啊,怎么能加ed呢?如果是过去时也是前面的be动词变化啊,我不懂了……请大家解答一下呢……
补齐句子就是：There are a lot of changes（which have） happened around us

楼上正解，文意是我们之间已经发生了很多变故