It's easier to go down a hill than to climb up a hill, so it is easier to have bad habits than to have good ones.

    Bad habits do not come 1. They come little by little while people do not notice their danger. Schoolboys pick up little bad habits in schools and in the streets. When they can't finish their 2 , they copy from their classmates. If they see older boys 3 , they also want to learn to smoke. When they grow older, their habits become 4 strong that they can no longer get rid of (除掉) it. From copying, they fall behind, and smoking is 5 for their bodies. At last they become worse and worse. How necessary it is that we get rid of the bad habits in the beginning!

******在杭州G20峰会工作总结报告中指出，广大市民识大体、顾大局，倾情奉献，自愿服务，为杭州峰会成功做出了重大贡献。从公民的政治生活的角度看，杭州市民G20峰会期间的倾情奉献启示我们（    ）