（1)Is that your a book? 哪里錯了your 和 a 不能同時使用改為：Is that your book?或：Is that a book?（2）This is a pen and that's a ruler? 應(yīng)為肯定句,因此去掉問號.（3）Is this his pencil?此題正確!...不好意思 我打錯了幾個（2）This is a pen and that's a ruler.沒有問號,但是有錯的（3）Is this his pencil？————Yes,it's（2）This is a pen and that's a ruler.沒有問號,但是有錯的 修改為：This is a pen and that is a ruler.此為并列結(jié)構(gòu)，is 最好縮寫，或者都縮寫（3）Is this his pencil？————Yes,it's應(yīng)該為：Yes，it is. is不應(yīng)縮寫。