句型转换（每空2分，共10分）
These are her pens. (改为一般疑问句)
            her pens?
What can I do for you?(改为同义句)
Can I            ?
I have a ping-pong bat. (改为否定句)
I          a ping-pong bat.
This blue shirt is nine dollars.(对划线部分提问)
__________  __________ is this blue shirt?
Are those your grandparents?
Yes,________ __________.(作肯定回答)