一、结构：
What/ How +被感叹的部分+ 主语+ 谓语！
What beautiful flowers they are !
二、变法：
一断，二加，三调位。
一断表示在谓语动词的后面断开，二加表示在断开的两部分中间加what 或how ,三调位表示前后两部分对调位置。
They had a good time yesterday .
一断：They had / a good time yesterday .
二加：They had（what）a good time yesterday .
三调位：What a good time they had yesterday.