If city noises ______ from increasing, people ______ shout to be heard even at the dinner table 20 years from now.
 
【正确答案】 A
【答案解析】 考查动词语态和时态。主语为city noises,谓语应用keep...from doing sth.的被动形式。20 years from now表示时态为一般将来时。故选A。