—I hear some noise in the next room.—Oh, yes. Your sister_______ there.
Walking alone in the dark, the boy whistled to __________ his courage.
I don't think the experiment is __________ failure. At least we have gained __________ experience for future success.
The party last night was __________ big success and all the people present had __________ great fun.
The two sportsmen congratulated each other __________ winning the match by shaking hands.
The development of the city's industry __________ its environment pollution.