This's an apple.That is a pear这句话错在哪?

This is ________ pear. That’s ________ apple. A．a...a B．an.. These are an apple and a pear.还是This is an apple and a pear. （）1.This is () pear and that is () apple.A.a,an B.a,a C.an,a This is an apple,that's a knife 1.This is an apple.(用a pear改为选择疑问句) 2.Tom's hair is blond.（b That's a ruler.对 a ruler 提问.Is this an apple?改为复数句子. Hi,Alice!What's this in English?This is an apple.请告诉我这句话哪里错了 This is a apple.It's red错在哪里 is it a pear or an apple?（用pear回答） 英语里 是 There is an apple and a pear 还是 There are an apple and 变复数1.This is a knife2.That is an apple tree3.He is a policem Here is an apple and a pear on the table.正确还是Here are an app