Was it in the barbershop that you used to go to that you saw the wanted man.
It is not their success that surprises me most but their diligence that does.
It was until the 19th century that people started sailing across the ocean.
It was when I pointed out his mistakes that he has just realised it.
It is the people who devote themselves to the science that promote the development of society.
考的是強(qiáng)調(diào)句的使用吧