They are ----(crazy)about dancing and singing.

They are ----(crazy)about dancing and singing.
They are ----(crazy)about dancing and singing.

They are ----(crazy)about dancing and singing.
楼主,就用Crazy原型就可以.
因为be crazy about是一个固定搭配.
所以是They are crazy about dancing and singing.
值得一提的是,be crazy about 后面要用动词进行时doing来搭配1

crazy
解释：be crazy about 表示“着迷于”。
祝你学习进步，更上一层楼！(*^__^*)

太简练了，问什么都不带说一句的

crazy (痴迷于）