请教专家老师：
However,there is an even more insidious kind of pollution that particularly affectsurban areas and invades our daily lives, and that is noise. Burglar alarmsgoing off at any time of the day or night serve only to annoy passers-by and actually assist burglars to burgle.Car alarms constantly scream at us in the street and are a source of profoundirritation. A recent survey of the effects of noise revealed that dogs barking incessantly in the night ratedthe highest form of noise pollution on a scale ranging from 1 to 7. The surveyrevealed a large number of sources of noise that we really dislike. Lawn mowerswhining on a summer's day, late-night parties in apartment blocks, noisyneighbors, vehicles of al kinds, especially large container trucks thunderingthrough quiet village, planes and helicopters flying overhead, large radioscarried round in public places and played at maximum volume. New technology hasalso made its own contribution to noise. A lot of people object to mobilephones, especially when they are used in public places like restaurants or onpublic transport. Loud conversations on mobile phones invade our thoughts orinterrupt the pleasure of meeting friends for a quiet chat. The noise pollutionsurvey revealed a rather spurring and possibly amusing old fashioned source ofnoise. It turned out to be snoring! Men were found to be the worst offenders.It was revealed that 20% of men intheir mid-thirties snore. Thisfigure rises to a staggering 60% of men in their sixties. Against these figures, it was found that only 5% of women snore regularly, while therest are constantly woken or kept awake by their trumpeting partners.Whatever the source of noise, one thing is certain: silence, it seems, hasbecome a golden memory.
1）onlyto...这里是出人预料以外的结果状语吗？谓语动词rated 感觉应该用被动语态，即was rated才合理呀？
2）2个宾语从句中的谓语动词snore若是正式语体都需要改成snored吧？谓语动词rises是一般目前时，所以，against these figures 中的figures是包含一般过去时中的20%和一般目前时中的60%？感到非常难理解句意？
3）这一句it was found that only 5% of womensnore regularly, while the rest are constantlywoken... 主句是过去式，而从句却是目前时，如何理解含义呢？困惑。这种while（对比）是并列连词还是从属连词呢？
1 serve to do sth，意为起...有哪些用途，带来...的结果。only在此表示仅仅、只的意思. 不是一般所说的表示出人预料的不好的结果。 rate可与物，也可以不及物。在此为不及物使用方法。你读这个句子时，应该掌握rate的不及物使用方法，而不是去改动句子。
2 根据主谓一致的原则，主句为一般过去时，名词性从句谓语应该用相应的过去时。但目前常见同意了假如从句的内容在说话时依旧有效就能用目前时。The noise pollution survey这个调查应该是作者写文章前不久公布的。所以作者在主句用一般过去时表示调查发现、揭示，但调查结果内容由于在目前依旧有效，就都用一般目前时表示了。既然figures是复数，一定指20%和60%。既然女人只提及5%，不做区别，就意味着30多岁和60岁女人打鼾没差异，都是百分之五。这就是作者对你说的。
3 主从句的时态不同和2是什么原因相同。while有人觉得是并列连词，有人觉得仍然是从属连词引导对比状语从句（夸克）。这不重要，你如何理解都可以。
