改病句：they are not carry flags and sing songs.
问题描述：
改病句：they are not carry flags and sing songs.
答
改为
they are not carrying flags and singing songs.
答
not后面加 to
答
They are not carrying flags or singing songs.
答
are 改为 do
答
carrying
singing
答
are改do，are 和carry 均为动词，一个句子中不可能有两个动词哦