Toughening
v. （使某物[人]）堅韌, 堅強, 強硬( toughen的現在分詞 )
??? 情景例句
They shared the first harvest with the Indians
他們與印第安人分享首次收成
I am very much thrilled to see this luxurious office.
看到這樣一個高層次的分支機構我感到很激動。
The ground supported fewer plants, and the insects which lived on these plants died out.
地上長的植物少了，生活在這些植物上的昆蟲就消亡了。