What delicious food it is (同义句)

问题描述:

What delicious food it is (同义句)
填空
( )delicious ( ) a ( ) is
可是练习上就是这么写的啊,你的答案为啥要加that啊?

How delicious that the food is
应该能这么写吧.food是不可数名次,咋能用a
初中经常有what转how的练习啊