单项选择题
A．the mayor has agreed with the teachers' union B．the teachers' strike will last long C．students haven't been to school for two weeks D．the mayor was trying to end the schools
A．visit the U. S. and Western Europe to improve the ties between China and them B．come closer to the U. S. and Western Europe C．close the door of China to the U. S. and Western Europe D．improve the ties between the U. S. and Western Europe
A．smiling does good to health B．laughter can be tolerated C．there is a way to reduce pain D．laughter can work the muscles in the feet