1.形容词，明智的;明智;可取；反义词： inadvisable
Early booking is advisable.
早订票是明智的。
It is advisable to book early.
宜提早订票。
It will be advisable for you to drop an acquaintance such as John; he is not a good companion for you.
你和约翰那样的人断绝往来是明智的，对于你他并不是一个好伙伴。
It is generally not advisable for expectant mothers to travel by air after the 28th week of pregnancy.
怀孕28周以后的准妈妈一般不宜乘坐飞机出行。
It may be advisable to have a blood test to put your mind at rest
最好验一下血，好让你自己放心。
It is advisable to mix coarse grit into heavy soil to improve drainage.
建议将粗砂掺到黏重的土壤里，以提高排水性能。
2.英语里有些形容词在意义上与情态或意愿有关，如advisable，当用先行词it充当主语，而用它充当表语时，则that从句（主语从句）的谓语动词用现在时虚拟式（美国英语）或用should 动词原形；（英国英语）,如：
It is advisable that we ( should) stay at home instead of going to the movie.
我们还是不去看电影，呆在家里好。
I don't think it advisable that Tim be assigned to the job since he has no experience.
我认为最好不要派蒂姆担任那项工作，因为他毫无经验。（研考真题）
类似用法的形容词还有：
essential重要的，必不可少的[ɪˈsenʃl]
important重要的
necessary必须的
strange奇怪的
imperative非常必要的,当务之急的[ɪmˈperətɪv]
vital至关重要的
impossible重要的
obligatory必须的
appropriate适当的[əˈprəʊpriət , əˈprəʊprieɪt]
desirable好的，所希望的
preferable更好的
It is essential that you have some experience.
你必须得有些经验。
It is essential that we present a united front.
至关重要的是我们要表现得团结一致。
It's essential you make the right decisions from the word go.
关键是从一开始就作出正确的决定。
It is important that he （should） attend every day.
他每天都要出席，这很重要。
It's very important to me that you should be there.
你应该到场，这对我很重要。
It is necessary that she （should）come here twice a week to help do the room.
她有必要每周来这里两次来帮忙打扫房间。
It is necessary that he listen to the radio frequently.
她很有必要常听收音机。
It is strange that he (should) have so many friends.
真奇怪，他居然有这么多的朋友。
It is absolutely imperative that we finish by next week.
我们的当务之急是必须于下周完成。
It was imperative that he act as naturally as possible.
最重要的是他要做到尽可能自然。
It is imperative that the above rules be strictly observed.
上述规定希严格执行为要。
It is vital that you keep accurate records when you are self-employed.
干个体的要准确记录账目，这十分重要。
It is vital that we act to stop the destruction of the rainforests.
至关紧要的是，我们应当采取行动制止破坏雨林。
It's vital we are as fresh as possible for those matches
尽可能保持旺盛的精力参加那几场比赛对我们来说至关重要。
《柯林斯高阶英汉双解学习词典》
这个例句说明 vital这个用法是选择性的。
It is impossible that he (should) forget our meeting; he must have stayed away on purpose.他不可能忘记我们的会议，他准是故意不来。
It is impossible that a single shot of education, administered in childhood and early adulthood, will be able to support a sustained, 60-year career.
只在童年和成年初期接受的一次教育不可能支撑持续60年的职业生涯。
四级真题- 2019年 6月
这个例句说明 impossible这个用法是选择性的。
It is obligatory that all employees (should) wear protective clothing.
所有员工必须穿防护服装。
It is obligatory that every young man serve in the armed forces.
每个年轻人都有义务在军队服役。
It is appropriate that Irish names dominate the list
名单上大部分是爱尔兰名字，这没什么不合适的。
It is appropriate that everyone be suitably attired.
人人穿戴得体是恰当的。
It is appropriate that he should get the post.
由他担任这一职务是恰当的。
It is appropriate that we (should) plant trees at this time.
现在我们植树是恰当的。
It is desirable that he ( should ) attend the conference.
他参加会议是可取的。
It is desirable that interest rates （should） be reduced.
利率下调是可取的。
It is desired that we（should）get everything ready this evening．希望我们今晚一切都准备就绪。
It is natural that she should do so. 她这样做是很自然的。
insistent
urgent
compulsory,
crucial
probable,
proper
advised,
arranged,
commanded,
demanded,
desired,
ordered,
proposed,
recommended,
requested,
required,
suggested
也有类似用法，是四六级考研等考试中俯拾皆是，不再一一举例。
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