Homework.

Thanks for sharing [이름]! Hope you always enjoy your meal. ^^

~~Teacher May~~

The most expensive restaurant that I have visited to is the hotel Shilla.

>> The most expensive restaurant that I have visited is Shilla hotel.

or >> The most expensive restaurant that I have been to is Shilla hotel.

It is a exclusive buffet that is located in the middle of Seoul city.

>> It is an exclusive buffet that is located in the middle of Seoul city.
 here are all kind of food prepared in the restaurant.

>> There are many kinds of foods prepared in the restaurant.

I could eat all kind of Asian, Europe and American food.

>>  I could eat all kinds of Asian, European and American foods.

I haven\'t seen some food in there.

>> I haven\'t seen some food there.

I went there long time ago so, I don\'t remember when I visited there. 

>> I went there a long time ago so, I don\'t remember the time when I visited. 
 I went to the hotel buffet with my colleagues.

>> CORRECT

Actually, it was prepared for the staffs putting their efforts during a year.

>> Actually, it was prepared for the staffs who worked hard in that year.

Our manager would like to encourage staffs by providing nice meals.

>> Our manager encouraged the staffs by providing nice meals.