【推荐1】Theory and practice are two sides of ________ same coin, which depend on each other. （用适当的词填空）

【推荐2】We met a _________ (profession) archaeologist at the _________ (enter) to the Great Pyramid, who explained to us _________ process of building such a difficult structure. (所给词的适当形式填空)

【推荐2】________ (cover)an area about three times ________ size of Yellowstone National Park, the GPNP will be one of the first national parks in the country. .(所给词的适当形式填空)(用适当的词填空)

【推荐3】It was________cold winter night and the moon was shining brightly across________night sky.