Guests at this hotel can use the gym at no extra cost.为什么用no extra cost前用at?

Guests at this hotel can use the gym at no extra cost.为什么用no extra cost前用at? Guests receive dinner upon arrival at the hotel 等于什么.=Guests receive dinner______ ______ ______ ______ ______at the hotel . some of the guests arrived at the rainbow hotel at 5:00.(一般疑问句） 简单句变复合句 This is the hotel.I stayed at the hotel last week. 英译汉：the hotel provides foreign guests with very good service. the hotel provides foreign guests with very good service. The hotel p_____ water and food for guests This is the policy at our hotel,it's the policy of our hotel 这两句话有问题吗? at Garden Hotel at hotel travel desks in the hotel 还是at the hotel guests This is the hotel at which we're staying.which可以省掉吗? This is the hotel（ where they stayed）last month,为什么不是where they stayed at. the food is good at this hotel ,but the () is poor填什么 this is tom _____ the hotel.答案有at,in,on This is the hotel where we live at.这句话对吗?还是应该是这样This is the hotel where we live . at last they decided ＿＿this hotel to have the meetingA.at B.in C.for D.on