They are now under a great deal of pressure to tighten their airport _______.
A. secure
B. secured
C. securing
D. security
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You can check your email by _______ your mouse.
A. clicking
B. click
C. to click
D. clicked
Last week, they _______ the broken window with a new one.
A. have replaced
B. replaced
C. were replaced
D. had been replacing
The staff in the library are friendly and _______.
A. efficient
B. effective
C. affective
D. affectionate
The shoes I bought two days ago have not been _______ yet, which makes me very anxious.
A. sold
B. delivered
C. priced
D. bought
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