有的石头像莲花瓣,有的像大象头,有的像老人,有的像卧虎,有的错落成桥, 有的兀立如柱,有的侧身探海,有的怒目相向. Some bore no resemblance to anything known , but glowered black and motionless, blocking your way.
The parrot squawked and flew away.鹦鹉尖声叫了叫飞走了。If you have not kept a pet parrot before, it would be wise to purchase a handbook on the subject.如果以前没有养过鹦鹉，最好买一本相关的饲养手册。He keeps a parrot in a birdcage in his living room.他在客...
A vertex with zero outdegree is called a sink.出度为零的顶点称作收点.Vertex a is the initial vertex and b is the terminal vertext.a顶点是始端顶点,而b是末端顶点.An edge corresponds to a corridor and a vertex to the conjunction of several corrido...