根据描述写出所描述对象的英文单词.
问题描述：
根据描述写出所描述对象的英文单词.
a kind of high building of Buddhism or a high building in the similar shape
the main stem of a tree usually covered with bark
an outdoor activity consisting of walking in the natural environment
a button on the telephone which may be pressed if you can't get through
答
stupa
trunk
hiking
redail