.A computer is so useful a machine ________ we can use everywhere.

Success for Li Ning was _________, with its attractive designs and reasonable prices. 

According to the rules of the factory, you can ask for leave ________ you have a doctor’s diagnosed note.

Don’t you know that Australia was, as a matter of fact, _________ used to be a nation of prisoners!

Perhaps most puzzling of all, _____ able to make sense of _____ we heard and distinguish the mistakes and errors from “good” language?