—Do you know the most ancient city in China—Xi’an well?—No,this is the first time I ________ here.
It has always been the _____ of our firm to encourage workers to take part in social activities.
The most important _____ of his speech was that we should all work whole-heartedly for the people.
When I worked as the general manager of the firm, I sometimes had _____ to visit London on business.
These plastic flowers look so _____ that many people think they are real.
It is clear that the whole world is passing through a social revolution in which a central _____ must be taken by scientists and technologists.