你想了解其他人的家庭和朋友吗？请你熟练地说出以下对话。

　　(1)－Is this your sister?

　　－No, it isn't.

　　(2)－Is that your brother?

　　－Yes, it is.

　　(3)－Is he your brother?

　　－No, he isn't. He's my friend.

　　(4)－Is she your sister?

　　－Yes, she is.

　　(5)－Is Li Lei your friend?

　　－No, he is my brother.

用am，is或are填空，然后总结其用法。

(1)That's my father and this ________ my mother.

(2)This is my cousin and that ________ my sister.

　　(3)－________she your sister?

　　－Yes, she ________.

　　(4)－And ________ he your brother?

　　－No. He's my friend.

　　(5)－________ Guo Peng your brother?

　　－Yes, he ________.

(6)I ________ his friend. I'm not his brother.

　　(7)－________ you Jack's brother?

　　－No, I'm not. I ________ his cousin.

(8)These ________ my grandparents.

　　(9)－________ this your aunt?

　　－Yes, it ________.

(10)These ________ my parents, those ________ my grandfather and grandmother.

(11)These are my brothers. They ________ Jeff and Jack.

(12)They aren't my sisters. They ________ my friends.

am用于第一人称单数I之后；is用于第三人称单数ge，she，it以及相当于he，she或it；are用于第二人称或所有人称的复数，表达“是”的意思。可用下面的口诀来帮助记忆：“我用am你用are，is用于他她它，复数全都要用are”。

I am…可以缩写成I'm，he is可以缩写成 he's，she is可以缩写成加she's，it is可以缩写成it's，而we are，you are，they are可分别编写成we're，you're，they're。am，is，are的否定形式是在后面加not，如：am not，is not，are not。is not通常缩写为isn't，而are not通常缩写为aren't。如：

(1)I'm Alice, I'm not Mary. She's Mary.

(2)This isn't my brother. He's my cousin.

(3)They're my brothers. They aren't my friends.

Find the best responses from the box.

[　　]

A．C－L－O－C－K

B．Nice to meet you, too.

C．That's all right.

D．No, they aren't.

E．Thank you.

F．They're in the backpack.

G．No, it isn't.

H．7122580.

I．Yes, I do.

J．Yes, she does.