| 1. | It is necessary that he should do so . 他这样做是必要的。 |
| 2. | It is necessary that we do this in our construction . 在建筑工程中我们需要这样做。 |
| 3. | To appreciate the unsteady environment existing in liquid propellant rocket chambers it is necessary that the steady state be well understood . 为了分析液体推进剂火箭发动机燃烧室中存在的非稳态环境,必须很好地了解稳态状态。 |
| 4. | It is necessary that he ( should ) be sent there at once 有必要立刻马上派他到那里去。 |
| 5. | It is necessary that he be sent there at once 有必要马上派他到那里去。 |
| 6. | It is necessary that those machines should be lubricated regularly 那些机器必须经常上润滑油。 |
| 7. | It is necessary that he ( should ) come to our meeting tomorrow 他有必要来参加我们明天的会议。 |
| 8. | It is necessary that we make enough arrangements for the meeting 我们为会议做好充分准备是必要的。 |
| 9. | It is necessary that the students ( should ) remember all the new words 学生记住所有的新单词是必要的。 |
| 10. | It is necessary that he ( should ) sort out the information for my reference 他有必要整理些资料供我参考。 |