已知二元一次方程2x﹣y=1，用y的代数式表示x为（　　）

    I'm very glad to tell you something about the Spring Festival. It's a ____ (传统的) festival in China. Chinese people ____ (庆祝) the Spring Festival happily. During the festival, people visit friends and ____ (亲戚).They ____ (招待) each other with ____ (和蔼) and warmth. They also give each other ____ (礼物), ____ (传播) love and joy. People eat lots of delicious food such as meat, vegetables, fruit and ____(甜点). Sometimes people go out to ____ (欣赏) the mountains and rivers. Many people put on several ____ (磅) after the Spring Festival.

孙中山在领导中国民主革命的斗争中愈挫愈奋，直到临终前还在遗嘱中告诫革命党人：“革命尚未成功，同志仍须努力。” 这里“革命尚未成功”主要是指(    )