-- _____is that used for?---_____ the floor.
When a space shuttle has accomplished its _____, it can be ready for another trip in about two weeks.
People cannot but feel _____, for they simply cannot understand how he could have made such a stupid mistake.
What makes the space shuttle _____ is that it takes off like a rocket but lands like an airplane.
Alice was very sorry to hear that her grandmother had _____ two days before.
Comrade Li Dazhao, _____ librarian of Beijing University, was one of the founders of the Chinese Communist Party.