Even rudimentary feathers on forelimbs could have expanded the arm's surface area to enhance lift slightly.
即使是前肢发育不全的羽毛也能扩大手臂的表面积，以略微提高升力。
2
Traditional downtown Xian refers to the area encircled by the city wall, this has now been expanded to encompass the area within the second ring road (er 'huan Lu).
传统的市中心区是指被西安的城墙包围的地区，现在已经被扩大到包括在二环路的区域。
3
Li indicated that currently the development of bilateral relations enjoys sound momentum with an increasing of common interest between both countries and cooperative area steadily expanded.