求各位高手帮忙做一道英语题，急急急~半小时之内完成，在下感激不尽，给高分

1.I went into the room without knocking at the door
2 Why don't you going by bus instead of going by train?
3 Ileft the hotel and paid my bill
4 I left the hotel and took a taxi to the airport 3题和4题没有给出连接词，这个是我自己理解的！
5 I must apologize for that I had't phone you yesterday
6 You should congratulate on my success of the competition

I went into the room without knocking at the door .
Why don't you go by bus instead of by train .
I left the restaurant paying my bill （没有给出连接词）
I left the hotel and took a taxi to the airport .（没有给出连接词0
I must apologize for not calling you yesterday .
You should congratulate me on my competition .