1, This 这个，这 （单数） This is your pen. Is this your pen? Yes, it is . No, it is not./ No, it isn’t. 2, That 那个，那 （单数） That is your book. Is that your book? Yes, it is . No, it is not./ No, it isn’t. 3, these 这些 （复数） These are your pencils. Are these your pencils? Yes, they are. No, they are not./ No, they aren’t. 4, those 那些 （复数） Those are your pencils. Are those your pencils? Yes, they are. No, they are not./ No, they aren’t. 本文来源：https://www.wddqw.com/doc/ce1cef1408a1284ac950439b.html