单选题 Hotel employees are reminded to be ______ and courteous, especially to first-time guests.
A. friend B. friends C. friendly D. friendship

【正确答案】 C
【答案解析】[解析] 我们提醒饭店员工礼貌谦让，尤其是对第一次到访的客人。横线处需填入be动词的表语。故正确答案为C。