用作形容词																				(adj.)
										
									
																																														
												用作定语
											
																																																								
														~+ n.
													
																								
																																																																							- 
															My money came short of the necessary sum.															
我的钱不足所需的数目。
															 
																													- 
															Do you have the necessary skills for this job?															
你具备做这项工作所必需的技能吗?
															 
																													- 
															They joined the wires and made the necessary new connection.															
他们把电线接了起来,接通了所需的新线路。
															 
																													- 
															I'll leave it to you make the necessary arrangements.															
我将让你作出必要的安排。
															 
																													- 
															The lawyers will draw up all the necessary papers.															
律师们将拟定出所有必要的文件。
															 
																													- 
															No one foresees how the necessary restriction of the population will be effected.															
任何人都无法预知将如何实现对人口的必要限制。
															 
																													- 
															They will meet in Beijing to debate taking necessary actions against environmental pollution.															
他们将在北京会晤并讨论采取必要措施防止环境污染。
															 
																							 																														
																																																																				
												用作表语
											
																																																								
														S+be+~
													
																								
																																																																							- 
															A year's guarantee on the television set for all repairs might be necessary.															
必须为电视机提供为期一年免费修理的保单。
															 
																													- 
															A climber must learn to discriminate as to when compass bearings are necessary and when they are not.															
一个登山者必须学会辨别什么时候需要罗盘测定方位,什么时候不需要。
															 
																													- 
															Under certain conditions, answering back sarcastically is necessary.															
在某种情况下,反唇相讥是必要的。
															 
																							 																														
																																																									
														S+be+~+ prep .-phrase
													
																								
																																																																							- 
															Patience and understanding are necessary for a teacher of infants.															
耐心和理解是幼儿教师必不可少的。
															 
																													- 
															What is necessary for one person is not always necessary for another.															
对某人来说是必需的东西,对别人则未必如此。
															 
																													- 
															These reference books are necessary to scientists.															
这些参考书是科学工作者所必需的。
															 
																													- 
															Sleep is necessary to one's health.															
睡眠对健康是必要的。
															 
																							 																														
																																																									
														It is/was+~+(for sb) to- v
													
																								
																																																																							- 
															It was necessary to jump on the ice coated mounds of brush several times before they could flush.															
你得在这些被冰覆盖的树丛上跳上好几下,才能把它们惊起。
															 
																													- 
															It's necessary to raise wages on the basis of increasing production.															
需要在增加生产的基础上增加工资。
															 
																													- 
															Because the company was doing more business, it was necessary to expand the factory.															
由于公司业务的扩大,扩大工厂是必然的。
															 
																													- 
															It was necessary to retire several generals who lacked energy and enterprise.															
使几位缺乏精力和上进心的将军解职是必要的。
															 
																													- 
															It is sometimes necessary to indulge a sick child.															
迁就一个生病的小孩有时是必要的。
															 
																													- 
															It is both important and necessary to note this difference.															
注意到这个差别是重要的和必要的。
															 
																													- 
															Is it really necessary for me to attend the meeting?															
我真的必须出席会议吗?
															 
																													- 
															It's necessary for us to net the currant bushes.															
我们有必要用网盖上红醋栗树。
															 
																													- 
															It is necessary for them to decide on which type of fuel is most suitable.															
他们必须决定哪一种燃料最合适。
															 
																							 																														
																																																									
														It is/was+~+that-clause
													
																								
																																																																							- 
															It is necessary that everyone be there in time.															
大家都按时到达那里是必要的。
															 
																													- 
															It's necessary that young and old people should communicate more with each other.															
年轻人和老年人有必要保持更多的联系。
															 
																							 																														
																																																																				
												用作宾语补足语
											
																																																								
														S+V+O+~
													
																								
																																																																							- 
															We consider it necessary that the machine should be oiled regularly.															
我们认为机器必须定期加油。
															 
																													- 
															This has made it necessary for agriculture and industry to develop very quickly.															
这就使得工农业必须飞速发展。
															 
																													- 
															I felt it necessary to speak about our shortcomings.															
我觉得有必要谈谈我们的缺点。
															 
																													- 
															Some students hold it necessary to be able to speak English.															
有些学生认为能讲英语是非常必要的。
															 
																							 																														
																																																																				
												其他
											
																																																							
																																																																							- 
															The National People's Congress holds one session each year. When necessary, the session may be advanced or postponed.															
全国人民代表大会每年召开一次会议,必要时,会期可以提前或推迟。
															 
																													- 
															If necessary, the heavy machinery can be brought into action.															
若有必要,可以使用重型机械。
															 
																													- 
															If necessary,I'll go there again.															
如有必要,我会再去那里的。