U字英语绕口令 ，
An undertaker undertook to undertake an underta-king.
The undertaking that the undertaker undertook was the hardest undertaking the undertaker ever undertook.
一个办事员办了事。办事员办的事是办事员办过的所有事中最难的事。
who that in youth no virtue uses, in age all honour him refuses.
年轻不讲品性，老来不受尊重。
The U.S. twin-screw cruiser.
美国双螺旋浆巡洋舰。 ，
