That is a book.
疑问句：
Is that a book?
否定回答：
No,it isn't.
This is my dictionary.
一般疑问句：
Is this your dictionart?
肯定回答：
Yes ,it is.
That's an English book.English book 是划线部分吧?
提问句：
What's that?
连词成句
Excuse me,is this your pencil box?