句型转换。

1. His baseball is under the table. (变为一般疑问句)

   _____ his baseball _____ the table?

2. His dresser is next to his bed. (变为否定句)

   His dresser _____ _____ next to his bed.

3. My keys are on the sofa. (对画线部分提问)

   _____ _____ my keys?

4. Mike is behind the door. (对画线部分提问)

    _____ _____ behind the door?

5. I draw pictures on the wall. (变为否定句)　　

   I _____ _____ pictures on the wall.

给水除氧的方式有哪两种？我车间的除氧器属那种类型？