Air purifiers(净化器) do more than clean the air in your house.It is one of the best 　1　(tool)that can improve your sleep.However,only clean air purifiers can help you sleep 　2　(peaceful).Air purifiers 　3　 blocked filters(过滤器) may produce a loud noise.That will never make you fall asleep.Instead,it will wake the person 　4　 is trying to sleep in the next room.Make sure you clean the filters of the air purifiers frequently so that they don’t just purify the air,but also avoid 　5　(produce) any uncomfortable noise. 
At the same time,check them frequently to ensure that they 　6　(be) in proper working order. 
You can either clean the filters alone or ask a professional to do it for you.For DIY cleaning,you can go online and search for 　7　(person) care user manuals (指南)to know 　8　 to take apart the filters and clean them.It is possible to use a vacuum cleaner to suck the dust 　9　(attach )to the filters.For some air purifiers,the filters can 　10　 (take) out.You can clean them using liquid soap,and put them back in the purifiers again. 
（A）
1.tools　考查名词。句意:这是改善睡眠的最佳工具之一。the best为形容词最高级,修饰名词,设空处需填名词,tool意为“工具”,是可数名词,one of后面需加可数名词复数形式。故填tools。
2.peacefully　考查副词。句意:然而,只有清洁的空气净化器才能帮助你平静地入睡。设空处修饰动词sleep,需填副词。故填peacefully。
3.with　考查介词。句意:过滤器堵塞的空气净化器可能会产生很大的噪音。设空处需填介词“带有,具有”,故填with。
4.who/ that　考查定语从句。句意:相反,它会吵醒隔壁房间试图入睡的人。设空处引导定语从句,从句缺少主语,需用关系代词引导,先行词是person,指人,需用关系代词who/that。
5.producing　考查非谓语动词。句意:确保你经常清洁空气净化器的过滤器,这样它们不仅能净化空气,还能避免产生任何令人不舒服的噪音。avoid doing sth为固定用法,故填producing。
6.are　考查时态和主谓一致。句意:同时,要经常检查,确保其工作状态正常。设空处缺少谓语动词,此处陈述客观事实,需用一般现在时,主语为they,谓语动词需用复数形式。故填are。
7.personal　考查形容词。句意:对于DIY清洁,你可以上网搜索个人护理用户手册,了解如何拆卸和清洁过滤器。设空处修饰名词care user manuals,需用形容词作定语。故填personal。
8.how　考查不定式的复合结构。设空处构成不定式的复合结构,需用副词how作方式状语。故填how。
9.attached　考查非谓语动词。句意:可以用真空吸尘器吸附在过滤器上的灰尘。已有谓语动词,设空处需填非谓语动词作后置定语,be attached to为固定短语,意为“依附在……”;此处需填过去分词形式。故填attached。
10.be taken　考查被动语态。情态动词can后面需加动词原形,主语the filters和take为被动关系,需用被动语态。情态动词can的被动语态形式是:can be done。故填be taken。