按要求完成下列句子。
1. We are making a model plane. (改为一般疑问句)
________________________________________________
2. The boys are sitting under the tree. (对画线部分提问)
________________________________________________
3. Look out of the window. (改为否定句)
________________________________________________
4. We can see some birds over there. (对画线部分提问)
________________________________________________
5. The children have some apples. (改为单数句)
________________________________________________
