Điền '' is , am , are ''
1. Which class ..are...you in ?
2. Whichs grade ..are..they in ?
3. .....is..your mother young? 
4 . .....is...your father young ?
5. Where ...is..the cat ?
6. Where ...are...the boys ?
7.Who .are...those ?
8. Mai and I ...are..ten yaars old .  We .are...in the same class
9. What ..are...their names. They ..are..lan and hoa .
10 What nationality ..is..Mrs Brown ? 
11 What color ..is.her dress ?
12 What color ..are.. his shorts ?