it's a pity 为什么pity要加a,it's a help和it's a pity是一样的形式吗?为什么有的名

it's a pity 为什么pity要加a,it's a help和it's a pity是一样的形式吗?为什么有的名 what's a pity和it's a pity a pity it's Sunday. It's a pity..的疑问 It's a pity..的疑问 It's a pity that know you. It's a pity that you are what a pity 和 it is a pity 的区别 that's a pity It's a pity that none of you watched me___ --It's a pity that Mr.Smith died last night. It’s a pity you____ miss the wonderful film.