例句與造句

1. Originally, Grigorchuk's group " G " was constructed as a group of Lebesgue-measure-preserving transformations on the unit interval, but subsequently simpler descriptions of " G " were found and it is now usually presented as a group of automorphisms of the infinite regular binary rooted tree.
2. It's difficult to find binary rooted tree in a sentence. 用binary rooted tree造句挺難的