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单项选择题

The scientists have absolute freedom as to what research they think it best to______.

A．engage
B．devote
C．seek
D．pursue
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热门试题

单项选择题A．startedB．conductedC．replacedD．proposed

A．started
B．conducted
C．replaced
D．proposed

单项选择题It ______months since we ______ in Shanghai.

A．has been...were
B．is ...are
C．was...had been
D．had been...have been