下列措施中，哪一种对保持生态环境最有利？（   ）

阅读理解

   The Healthy Habits Survey(调查)shows that only about one third of American seniors have correct habits. Here are some findings and expert advice.
1．How many times did you brush your teeth yesterday?
·Finding：A full 33% of seniors brush their teeth only once a day.
·Step：Remove the 300 types of bacteria in your mouth each morning with a battery－operated toothbrush. Brush gently for 2 minutes, at least twice a day.
2．How many times did you wash your hands or bathe yesterday?
·Finding：Seniors, on average, bathe fewer than 3 days a week. And nearly 30%wash their hands only 4 times a day—half of the number doctors recommend.
·Step：We touch our faces around 3,000 times a day－often inviting germs(病菌)to enter our mouth, nose, and eyes.Use toilet paper to avoid touching the door handle. And, most important, wash your hands often with hot running water and soap for 20 seconds.
3．How often do you think about fighting germs?
·Finding：Seniors are not fighting germs as well as they should.
·Step：Be aware of germs. Do you know it is not your toilet but your kitchen sponge(海绵)that can carry more germs than anything else? To kill these germs, keep your sponge in the microwave for 10 seconds.

材料一：109年（1840－1949）沧桑巨变，换了人间。北京天安门，曾在1900年见证了西方列强的野蛮；在1919年见证了中国人民的觉醒；1949年的秋天，它终于迎来了一个崭新的共和国。为了这一天的到来，一代代中华儿女前赴后继，在这峥嵘百年中经历无数的艰难坎坷。

——《复兴之路》

材料二：井冈山根据地的建立，是***等老一辈革命家正确分析当时形势后作出的英明决策。1927年***率领秋收起义的部队在攻打长沙失利后，向井冈山进军。井冈山位于湘赣边界，那里地势险要，易守难攻；群众基础好，敌人统治力量薄弱；而物产丰饶，便于筹款筹梁。因此在井冈山建立革命根据地既有利于红军的全面发展，又有利于推动全国革命走向高潮。

材料三：***领导中国人民经过了28年艰苦卓绝的斗争，经过开天辟地迎来了曙光、生死攸关历史转折、在贫瘠的黄土高原达到了思想制高点，给与中国革命以灯塔指引，最后建立了新中国，开辟了中国历史新纪元。