Who\'s this?It\'s a cat.这句话错在哪里?

Who\'s this?It\'s a cat.这句话错在哪里? The cat is kate's.It's name is Mimi这句话错在那! This is a apple.It's red错在哪里 It's a cat .Its name is Mimi.有错没错,错在哪里 what's this?it's a cat变为复数句 Who it's this? "Who's books are these?""they are Tom's"这句话错在哪里 I think it's a exciting movie.这句话错在哪里 What's this --It is an backpack.这句话哪里错了 What's this?It's a pen.这句话是对是错 What's behind the door?It's a football.这句话哪里错了 Where is white cat?It's in the tree.错在哪里?怎么改?