根据下列句子及所给汉语提示，用单词的正确形式填空（每空一词）。
（1） He left the room without a(n) ___________ (解释).
（2）. The little tramp, acted by Charlie Chaplin, became known ___________ (遍及) the world.
（3）. We have very ___________ (令人信服的) evidence to show that he is the criminal.
（4）. Jody Williams started many ___________ (运动) to stop the making of landmines.
（5）. ___________ (不幸地), there’s nothing I can do about your problem.
（6）. The police are keeping the thief under close ___________ (观察).
（7）. Yuan Longping has been ___________ (努力,斗争) for Chinese farmers over the past decades.
（8）. The old buildings in Changchun are well ___________ (保存).
（9）. I can easily recognize your handwriting. It’s so ___________ (独一无二的).
（10）. Tony and I, ___________ (代表) our class, greeted international students at the airport.