It is well known that knowledge is________treasure house,but practice is________key to it.
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.
The speaker _____ several other subjects in the course of his talk but mostly kept himself to the main topic.
At first the institute refused to purchase the telescope, but this decision was _____ revised.