14.(expanse)广阔的一大片
15.the field
(place where practical work is done)实地；野外
They never have to go out into the field: they catch everyone on the Internet.他们从不用去实地, 因为他们都是在网上联系每个人。
16.(surface displaying design)(旗帜、钱币等的)底子, 底色；(纹章的)盾面
17.(field of view)(望远镜、显微镜等的)视野