The National Arbor Day Foundation has challenged many cities to earn its "Tree City USA" flag by planting and protecting more trees.
国家植树节基金会向许多城市发起挑战，要求它们通过种植和保护更多的树木来赢得那面“美国树城”的旗帜。
2
Kibara and hundreds of other farmers have been removing some of their tea bushes and planting a new kind of tea developed by the Tea Research Foundation of Kenya.
基巴拉和其他数百名农民不断移除他们的部分茶树，换成一种由肯尼亚茶叶研究基金会（Tea Research Foundation of Kenya）开发的新品种茶树。
3
Mr. Kibara and hundreds of other farmers have been removing some of their tea bushes and planting a new kind of tea developed by the Tea Research Foundation of Kenya.