单选题 ―How about your trip to Hainan? ―It couldn’t have been _______. Sometimes I went swimming in the sea; sometimes I lay on the sand.
【正确答案】 C
【答案解析】根据前后文句意可推知去海南的旅行非常愉快，此处是比较级的否定式表达最高级的含义，意思是“不能再好了”。