Section A (Grammar Focus3c,Unit 3Is this your pencil,课后作业,一、用所给代词的正确形式填空 1. John, is that _ (you) ruler? No, it isnt. Its _ (he). 2. Is this Marys book? No, it isnt _ (she). It is mine (I). 3. Are these pencils _ (you)? Yes. They are _ (I) pencils,your,his,hers,yours,my,4. Are these Susans erasers? No, these are not _ (she) eraser. Those are _ (she). 5. Hey, Frank. Here is _ (you) pen. It isnt _ (I). Its Jacks,her,hers,your,mine,二、按要求完成句子 1. This is m