I would loke to thank you and all of your associates at preston Travel --- your help in planning my business there involved --- new computer systems in several production facilities. The days were long and busy, but your advice --- transportation and local service helped me manage my hectic itinerary.
1. for 2. implementing 3. regarding
1번은 about은 왜 안되는지...ㅠㅠ
3번은 regarded가 답 같은데.. 도와주세요 고수님들