Before they h______ dinner,David and his parents cut a cake.
问题描述：
Before they h______ dinner,David and his parents cut a cake.
答
Before they h______ dinner,David and his parents cut a cake.
填had
答
had
Before they had dinner,David and his parents cut a cake.
大卫和他的父母在吃晚饭前切了块蛋糕