9. Men were found to be the worst offenders. 人类是这方面的罪魁祸首。
offend:惹怒   offender 罪魁祸首新概念

were found: 强调客观描述

 It is said...据说

 It is revealed...据批露

10. 20% of mem in their mid-thirties在他们35岁左右

对应的有：

in their early thirties 30刚出头

in their late thirties 将近40岁

11. 推荐背诵：Against these figures, it was found that ... 依据这组数字，和这组数字相比

也可以改成这种结构：Comparing these figures, we found that...

12. Whatever the source of noise, one thing is certain: silence, it seems, has become a golden memory.

对比一个句子：However you decide to spend your time, one thing is certain: you will arrive at your destination fresh and uncrumpled. （NCE3 Lesson44）