Nearly________ of the surface of our planet is covered by water.
| A．seven-ten | B．seven-tenth | C．seven-tenths | D．seventh-ten |
The bell _____ the end of the class rang, _____ our heated discussion.
| A．indicating, interrupting | B．indicated, interrupting |
| C．indicating, interrupted | D．indicated, interrupted |
As early as 1647 Ohio made a decision that free, tax supported schools must beestablished in every town _____ 50 households or more.
| A．having | B．to have | C．to have had | D．having had |
Although punctual himself, the professor was quite used _____ late for his lecture.
| A．to have students | B．for students' being |
| C．for students to be | D．to students' being |
The pressure _____ causes Americans to be energetic, but it also puts them undera constant emotional strain (过度紧张).
| A．to compete | B．competing |
| C．to be competed | D．having competed |
_____ it or not, his discovery has created a stir in scientific circles.
| A．Believe | B．To believe | C．Believing | D．Believed |