The rise of oil prices made scientists search for new energy re-sources to __________ oil.
| A．remove |
| B．replace |
| C．explode |
| D．explore |
Alice was very sorry to hear that her grandmother had _____ two days before.
| A．broken off | B．passed off |
| C．given away | D．passed away |
Comrade Li Dazhao, _____ librarian of Beijing University, was one of the founders of the Chinese Communist Party.
| A．sometimes | B．sometime | C．some time | D．some times |
The speaker _____ several other subjects in the course of his talk but mostly kept himself to the main topic.
| A．held on | B．worked out | C．touched on | D．kept out of |
At first the institute refused to purchase the telescope, but this decision was _____ revised.
| A．occasionally | B．consequently |
| C．successively | D．subsequently. |
No one imagined that the apparently _____ businessman was really a criminal.
| A．respectful | B．respectable | C．respective | D．respected |