题目

________to sunlight for too much time will do harm to one's skin. A．Exposed           B．Having exposed C．Being exposed         D．Having been exposed 答案：C“孔雀开屏”属于A．觅食行为学习行为B．防御行为先天性行为C．繁殖行为先天性行为D．攻击行为学习行为