The Spring Festival is coming soon. Do you want to have a trip during the Spring Festival? What about going to Beijing and Shanghai? They are big cities with a long history. You can also visit many famous places. Now Shunfeng Club, a travel agency(旅行社), has some tour groups for you this year. You can know more about the tour groups for Beijing by 0312－2345867, and the tour groups for Shanghai by 0311－5368745.

中新社西安2015年11月8日电最新对中国黄土高原进行的水土保持生态考察结果显示，黄河的年均输沙量已从16亿吨减少到本世纪的3亿吨左右，减幅达80%．但专家强调，黄土高原水土流失问题依然严重．下列措施对黄河输沙量减少影响最小的是（  ）

若x=2，y＝$\frac{1}{2}$，则x²+4xy+4y²的值是（　　）