Formorethanadecade,expertsfrom

For more than a decade, experts from across the globe ________ on the cure of the disease that way.

A．worked

B．are working

C．have been working

D．were working

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Paul doesn’t have to be made _______. He always works hard.

A．learn

B．to learn

C．learned

D．learning

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The boy wanted to ride his bicycle in the street, but his mother told him _______.

A．not to

B．not to do

C．not do it

D．do not do

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We agreed _______ here but so far she hasn’t turned up yet.

A．having met

B．meeting

C．to meet

D．to have met

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—You were brave enough to raise objection at the meeting.
—Well, now I regret _______ that.

A．to do

B．to be doing

C．to have done

D．having done

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The first textbooks _______ for teaching English as a foreign language came out in the 16th century.

A．having written

B．to be written

C．being written

D．written

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