Students are encouraged to _________ the design competition for robots at the university.
The manager meant ____ the workers that being 5 minutes late meant ____ the company.
Great changes ______ in China in the past 20 years.
The question is ______ it is worth doing.
The students were ____ over the ____ problem, listening to the teacher with a ____ expression on their faces.
---Would you mind my sitting here ____ lunch? ---______. A. and have, No, not at all C. and having, No, thank you. C. to have, Never, go ahead. D. and have, Oh, it’s my pleasure.