请问一下。Before my sister went for her interview, she researched the company on the Internet and consulted a few people.句中从句before有时间参照，为什么主句不用had researched呢？希望老师帮忙，谢谢了！
He looked round him with a furtive and stealthy air, as one who dreads pursuit. Then he vanished over the hill.怎么理解和分析as one who dreads pursuit？as在这里用法词性？ 这句话和前句的关系如何分析？
The exhibition, which opened this month at the National Museum of
African American History & Culture, begins in a war-ravaged plantation
house and ends with Georgetown University’s recent announcement of a bursary
for the descendants of 272 slaves sold to cover its debts.谢谢老师！
Last
August, city officials interviewed about 500 residents to find out people’s
attitudes to protecting the environment and what actions they had taken.句子摘自北师大高中英语必修第三册第8单元(p40)。请帮忙分析和翻译这个句子，谢谢。
...动词只要使用就要用过去时呢？比如 embarrass, catch,
buy, fail等等。The house catches fire.(误)You buy it.(误)The pants embarrass me.(误)I fail to persuade my father to give up the smoking.(误)学生认为有些词好像天生就有用过去式的含义，如果使用现在式...
...
第二句：In ______ review of 44 studies, American researchers found that menand women who ate six key foods daily cut the risk of _______ heart disease by79%. 空内分别填“a"和the"" 请详细的说一下，这三个空为什么这么填
She explained that Rastus was very dear to her.Considering the amount she paid, he was dear in more ways than one!这个是新概念3 lesson19 中的，这里为什么不用过去完成式 she had paid?
We ___67___ (concern) that few people would speak English, even in Beijing. But we found it common for Chinese people to know a few words of English这个句子是用过去时合适还是过去完成时合适，还是两个都可以呢？