necessary adj. 必要的,不可缺的;必须的,强迫的;必然的,必定的。 a necessary result 必然的结果。 a necessary evil 难免的危害[坏事]。 a necessary house 〔古语〕厕所。 be necessary to [for] 为…所必要。 if necessary 如果必要的话。 It is necessary that one should (do). =It is necessary for one to (do). 某人必须…。 n. 1.必需品;〔the necessary〕 〔口语〕必需的金钱[行动]。 2.〔美方〕厕所。 daily necessaries 日用品。 the necessaries of life 生活必需品。 provide [find] the necessary 〔俚语〕筹款。
It is necessary that we do this in our construction . 在建筑工程中我们需要这样做。
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。
It is necessary that he ( should ) be sent there at once 有必要立刻马上派他到那里去。
It is necessary that he be sent there at once 有必要马上派他到那里去。
It is necessary that those machines should be lubricated regularly 那些机器必须经常上润滑油。
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。
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。
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。
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。