My father and my mother have been married for 30 years, and never once ______ with each other

Andrew was afraid to fill the room with water again, so he __________ the pipe carefully.

People’s expectations about the future may have more influence on their sense of wellbeing than their ________ state does. [ ]

Every possible means_____ been tried，and we find only______ this means can we do it well．

ung man, who by then ___ admission to Peking University, determined to do some part-time jobs to gain more practical skills.