base n.指具体的有形的基础，也可指物体的底部、基部;基地，总部。
They use their apartment in New York as a home base from which they travel frequently.
他们把纽约的公寓作为他们频繁出行的大本营。
foundation n.本义指建筑物的地基，含有坚实的基础的意思;基金会。
The foundation for our house is made of cement.
我们房子的地基是水泥打下的。
ground n.地面，土地，也指地域，水底，海底。
A snake wormed on the wet ground.
一条蛇在潮湿的地上慢慢爬行。
The crane lifted the heavy stone from the ground.
起重机把沉重的石头从地上吊了起来。
I heaved him up and then put him down on the ground lightly.
我奋力把他举了起来，然后又把他轻轻地放到了地上。