Experiments of this kind____ in both the U.S. and Europe well before the Second World War.
A. have conducted B. have been conducted
C. had conducted D. had been conducted
_________ himself with necessary knowledge and skills, Tom went to the job market with much confidence.
A. Equipped B. Equipping
C. Having equipped D. Being equipped
No matter how frequently__________, the works of Beethoven always attract large audiences.
A. performed B. performing
C. being performed D. to be performed
---Would you like ____________, sir?
--- No, thanks. I have had much.
A. some more oranges B. any more oranges
C. some more orange D. any more orange
____________ with care, one tin will last for six weeks.
A. Use B. Using
C. Used D. To use
There are some health problems that, when _______ in time, can become bigger ones later on.
A. not treated B. not being treated
C. not to treated D. not have been treated
