A
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(细菌) 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.
【语篇解读】 本文为说明文。文章介绍的是一个对美国老年人进行的健康习惯的调查结果以及专家给出的对策。
21.What is found out about American seniors?
A.Most of them have good habits.
B.Nearly 30% of them bathe three days a week.
C.All of them are fighting germs better than expected.
D.About one third of them brush their teeth only once a day.
答案 D [细节理解题。根据第一个问题下Finding的内容“A full 33% of seniors brush their teeth only once a day.”可知D项正确。]
22.Doctors suggest that people should wash their hands .
A.twice a day B.three times a day
C.four times a day D.eight times a day
答案 D [推理判断题。根据wash their hands可锁定第二个问题下的内容，根据“And nearly 30% wash their hands only 4 times a day—half of the number doctors recommend.”可知，每天洗手四次只是医生建议的一半，由此可推知，医生建议的次数是每天8次。故选D项。]
23.The text probably comes from .
A.a guide book B.a popular magazine
C.a book review D.an official document
答案 B [文章出处题。本文显然不是书评(a book review)，也不是官方文件(an official document)。A项有较强的干扰性，但本文主要是面向公众的科学知识普及，而不是生活指南，故选B项。]
