按要求完成下列各题。
1. I had a good trip. (变为一般疑问句)
____________ ____________ ____________ a good trip?
2. It's 5: 15 pm. (就画线部分提问)
_______________________________________________________
3. This is our friend Danny. (变成否定句)
_______________________________________________________
4. He's at the airport. (就画线部分提问)
_______________________________________________________