将下列句子由单数变为复数形式或由复数变为单数形式 :
1. This is an eraser . ______ ______ _____
2. Is that your knife ? _____ _______ your _____?
3. - Whose T-shirt is this ? - It's mine .
- ______ ____ _____ ____? - ______ ______.
4. Those are eggs in English. ______ _____ ____ ______ in English.
These are erasers.
Are those your knives?
--- Whose T-shirts are these?
--- They are ours.
That is an egg in English.
1.These are erasers
2.Those are
2.Are those your knives