A

⑴Who are they? ____            

⑵Where did you live?____        

⑶Is this your grandpa?____       

⑷Did he learn Chinese ?____     

⑸What's he doing?____          

B

A.Yes, it is.               

B.They are my grandparents.

C.He's reading a book.     

D.No,he didn't.          

E.I lived in a small house.

物    质

X

Y

Z

Q

反应前质量/g

4

10

10

25

反应后质量/g

未测

35

1

9