情景交际我最棒，根据情景选择最佳答案。
1. A letter is __________ the table. 
[ ]
A. in
B. on
C. under
2. —Where is Xiaoyong?
—__________
[ ]
A. He's on the box
B. He is on the bed.
3. —What is this? 
— __________.[ ]
A. It's on the box.
B. It's a box.
4. He is swimming __________ the lake. 
[ ]
A. on
B. in
C. under
5. —__________?
—It's on the chair.[ ]
A. What is it
B. Where is the apple
C. How is the apple
6. She often __________ in the park. 
[ ]
A. flies kites
B. swims
C. walks
