A
根据短文内容，从短文后的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。
(2020•云南省昆明市第一中学高三模拟)
Easy Ways to Improve Indoor Air Quality
Indoor air quality tends to be worse in the winter months.That’s because there is often no flow of fresh air from the outside. 1 However，you can reduce the number.Here are some ways you can use to improve air quality inside your home and hopefully improve your allergy symptoms.
● Keep it clean. 2 It is because good indoor hygiene(卫生) can greatly cut down on dust and animal hairs，says Dr.BuSaba.Your cleaning efforts should focus on strategies to reduce the amount of mold(霉菌)，pet hairs，and dust in your home.
● 3 Even in the cold months，open windows from time to time to allow fresh air to move into the house.Also，move potential air pollutant out by using fans in the kitchen to remove cooking fumes.
● Keep the greenery outdoors.In-door plants are pretty，but they can also collect and promote the growth of bacteria.So，if indoor allergens are a problem，you’ll want to avoid them.While some plants are helpful in improving indoor air quality，they are still allergy causes for many people. 4
● Invest in an air purifier.If you’re allergic to indoor allergens and can’t control the source of the problem，it may help to use an air purifier. 5 You’re probably not going to be able to remove these allergens completely，but you can cut down on them.
A．Let the fresh air in.
B．Use indoor facilities properly.
C．It is a must in bitterly cold weather.
D．A clean house may be a healthier house.
E．On balance，they create more problems than they help.
F．For example，you’re unwilling to give up your family pet.
G．It’s probably impossible to remove all the allergens inside your home.
【答案】 1.G 2.D 3.A 4.E 5.F
【解析】 这是一篇说明文。介绍改善室内空气质量的简易方法，如保持卫生；多通风；不在室内养绿植；买一台空气净化器等。
1．段中题。根据设空后的转折关系可知，本空与本段第一句属同一范畴的语义，设空前讲冬季室内空气质量较差，室内缺乏新鲜空气流通。G项提到It’s probably impossible to remove all the allergens inside your home.(不可能去除家里所有的过敏原。)，符合文意。故选G。
2．段中题。根据标题“Keep it clean.”以及设空后陈述了清洁的室内卫生能大大减少灰尘和动物毛发。D项提到 A clean house may be a healthier house.(一个干净的家可能是一个健康的家。)空后句子与D项形成因果关系。故选D。
3．段首题。该段第二句提到“...open windows from time to time to allow fresh air to move into the house.”(要时不时的开窗让新鲜的空气进到房里。)，由此可知，本段主张开窗换气，A项提到Let the fresh air in.(让新鲜的空气进来。)符合文意。故选A。
4．段尾题。该段采用了对比的方式，第二句提到虽然绿植很好看，但也会相应的滋生细菌。第四句提到虽然能改善室内的空气质量，但还是有可能成为过敏原。由此判断，设空句与前句也应形成转折关系，与好处相比，危害更大。故选E。
5．段中题。举例解释空前句子。要是你不能改变室内的过敏原，比如自己喜欢的宠物，那可以通过购买净化器来降低过敏原带来的影响。故选F。
