these trials, people are ________assigned to a "treatment" group, which benefits from the project, and a "control" group, which does not.
A __________snow promises a good harvest next year.
—The cars give off a great deal of waste gas into streets. —Yes. But I'm sure something will be done to __________air pollution.
The performance of the host,__________ to please the audience and draw their attention, was greeted with a cold silence, however.
We __________a meeting when suddenly a womanbroke in.
He arranged __________ a man to meet his uncle at the station because he was busy with work.