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_____ it is very late now, the researchers are still working in the lab.
\_\_\_\__ it is very late now, the researchers are still working in the lab.
The American and the British _____ a large number of social customs.
The American and the British \_\_\_\__ a large number of social customs.
A new house _____ at the corner of the road.
A new house \_\_\_\__ at the corner of the road.
The development of industry has been _____ gradual process throughout _____ human existence, from stone tools to modern technology.
The development of industry has been \_\_\_\__ gradual process throughout \_\_\_\__ human existence, from stone tools to modern technology.