Their younger peers had a bit more luck, beginning their careers in years when tightening labour markets had pushed up wages. Until, that is, the covid-19 pandemic upended many of their lives. 请问一下老师，这个that is在这里是干啥的？
A gap before “who” made clear that he did not mean previous
African-American candidates lacked cleanliness, just that they had been less
“mainstream”.请问老师这里just that前面的逗号是表语气的停顿吗?还是其他的用法。
(1)They have helped us a lot,but we really fell sorry that we have nothing to give them in return.(2)What did he do in return for your kindness?请问老师,两句例句中的in return分别是做什么成分? 而in return for后接的内容是作为目的还是定语?
...其中的 onboard 的用法。查词典，onboard是形容词，只用作定语。根据词典上的例句，它后面修饰的名词都是指被安装的东西。如：Our new car has an onboard navigation system. 我们的新车上配有车载导航系统。he car comes with an onboard computer. ...
In 2014 HKEX sought to ride
the waves by launching Stock Connect, a conduit allowing offshore and mainland
punters to invest in each other’s markets.老师您好，请问这里的a conduit
allowing…是动名词的独立主格作同位语吗？
The
next thing he heard was an insistent knocking on the door of his room.这里的knocking是动名词吗？可以说成the insistent knocking of the door 这种结构吗？这种形式的doing词使用有哪些注意点，谢谢老师！