老师不好意思问题有点多，麻烦一下：
They allow young people to exchange moment-by-moment experiences in their daily lives with special partners and thus to have a more 42 sense of connection with friends.您说是并列的省略句 =thus the young people have那之前的thus to to可以被省略吗？
This nameless person pushed the human race over a historic threshold, for it was in that year that mankind became, for the first time in its history,a predominantly urban specues.其中over a historic threshold是时间状语 for the first time in its history也是时间状语和for it was in that year that mankind became a predominantly urban specues这个是for+强调句型？没见过这个结构
Migrants to cities are attracted by plentiful jobs这里的migrant to是省略了定语从句？
His main thesis is that the buzz of urban life, and the opportunities it offers for co-operation and collaboration, is what attracts people to the city,which in turn makes cities into theengines of art.....第一个that是同位语从句，第二个what是表语从句作主语，第三个which作thesis定语从句？
因为如果省略了 就是并列谓语 但它的逻辑主语 不是 句子主语 它的逻辑主语是句子宾语young people
This nameless person pushed the human race over a historic threshold, for it was in that year that mankind became, for the first time in its history,a predominantly urban specues.其中over a historic threshold是时间状语 for the first time in its history是for 并列句中的时间状语
for it was in that year that mankind became a predominantly urban specues这个是for+强调句型
for 是并列连词 可以并列一个完整的句子 表示原因 本句中 这个完整的句子 是对 时间状语强调的强调句型
= for mankind became a predominantly urban specues in that year
Migrants to cities are attracted by plentiful jobs这里的migrants是主语
to cities是介词短语 作定语 修饰migrants
这是介词短语作定语 与定语从句作定语 是两个概念。
His main thesis is that the buzz of urban life, and the opportunities it offers for co-operation and collaboration, is what attracts people to the city,which in turn makes cities into theengines of art.....第一个that是表语从句 说明主语 系动词后面说明主语的句子成分 叫表语 ，
第二个what是表语从句中 的表语从句中 ，第三个which引导的是非限制性定语从句 修饰的是整个 表语从句
2 是的。判断强调句的方法是去掉it is that后不缺少成分。显然it was in that year that mankind ……去掉it was that后 为in that year mankind……不缺少任何成分，所以是强调句
3 应该不是省略了定从吧，因为那样的话 to cities 也在从句中，应该一起省略，可它出现了。应该是一种固定的特殊用法吧
4 是的 这个定语从句中缺主语，而且动词又用的是makes，所以应是单数的thesis本回答被网友采纳
