A. as soon as they saw him B. as soon as he had finished cleaning himself C. as soon as he settled down D. some time after they first saw them 参考答案:D 答案解析:[解析] 该鸟首先cleaned himself然后才开始dance。
第23题: [单项选择]在现代医学模式的影响下,使得卫生服务发生了扩大,这主要表现在() A. 从预防服务扩大到治疗服务 B. 从心理服务扩大到生理服务 C. 从医院内服务扩大到医院外服务 D. 从社会服务扩大到医院内服务 E. 从照顾服务扩大到技术服务 参考答案:C 答案解析:现代医学模式下,卫生服务出现了四个扩大:一是从治疗服务扩大到预防服务;二是从生理服务扩大到心理服务;三是从医院内服务扩大到医院外服务;四是从技术服务扩大到照顾服务。