No smoking or eating ___(be) allowed.

No smoking or eating ___(be) allowed.
is 还是 are 为什么.
那About three quarters of the books and newspapers____(be)written in English呢?

is 当句子中出现or的时候,谓语形式遵循就近原则,所以用is
About three quarters of the books and newspapers____(be)written in English用are因为句子中有three quarters 是复数,所以用are
主谓一致：在英语句中,谓语受主语动支配,必须同主语在人称和数上保持一致.
＊名词＋as well as/no less than/but/except/with/like +其他名词,作主语时,谓语与前面的第一个名词一致.
＊few/a few/both/many/several+名词复数／of+名词复数＋复数
＊不定代词／疑问代词(something/anything/anywhere/somewhere/where/when)＋单数
语法一致原则：句子谓语动词的数取决于该句子主语的数.
1.“the＋姓氏名词的复数形式”(---的成员)＋复数 2.all/some/half/enough/two thirds ＋名词（单／复数）＋单／复数 3.复数形式的名词：clothes/trousers/shorts(短裤）/glasses/scissors/gloves/chopsticks等＋复数
＊ 计量单位（pair)＋ 复数形式的名词＋谓语取决于 计量单位
意义一致原则：谓语动词的单、复数形式,取决于主语所表达的概念.
1.集体名词：people/public(公共)/police/crew(船员）＋复数 2.复数形式,单数意义.（news/physics/maths/politics) 3.集合名词：class/family/team/Chinese/Japanese强调总体－－单数；强调个体－－复数.The class has 45 students. The class are planting trees on the hill.
4.时间、距离、价格、重量的复数名词／算式＋单数 Ten days is a long time.
5.the +形容词“表一类人”＋复数; The rich have much money.
6.and/both--- and + 复数 7.one of/each of/none of/either of/neither of ＋名词＋单数 8.a number(许多) +n +复数；the number (---的数量)+n +单数
9.名词＋and＋名词“表同一人／物用单数”“表不同人／物用复数”
The writer and the speaker are from the USA. The writer and speaker is from the USA.
就近一致原则：谓语动词的数要与它紧邻的名词／代词的数保持一致.
1.or/not--- but/either--- or---/neither--- nor---/not only--- but also--- ＋就近原则
2.There be＋并列主语
（一）主谓一致的种类
1．语法形式上的一致
主语为单数形式,谓语动词用单数形式；主语为复数形式,谓语动词也用复数形式.如：
The number of the students present is 200.
Jane and Mary look alike.
2．意义上一致
1）主语形式虽为单数,但意义为复数,谓语动词用复数.如：The crowd were shouting.
单数形式代表复数内容的词有：people, police, cattle等.
2）主语形式为复数,而意义上却是单数,谓语动词用单数.如：The news was so surprising.
形复意单的单词有news和一些以ics结尾的学科名称,如physics,politics, economics等.
3．就近原则
即谓语动词的单、复数形式取决于最靠近它的词语.如用连词or,either…or, neither…not, not only…but also等连接的并列主语,如果一个是单数,一个是复数,谓语动词与靠近它的主语一致.如：
Either your students or Mr. Wang knows this.
（二）主谓一致的应用
1．名词作主语
1）某些集体名词,如family, team等作主语时,如果作为一个整体看待,谓语动词用单数形式,如果就其中一个个成员而言,谓语动词用复数形式.如：
His family is a happy one.
The whole family are watching TV.
这类名词有：audience,class,club,company,crew,enemy,crowd,government,group,party,public,team等.
名词population一词的使用情况类似.“a group(crowd) of +复数名词”等短语之后的谓语动词也同样可用单数或复数,前者强调整体,后者强调各个部分.
2）某些集体名词,如people, police, cattle等,只当复数看待,谓语动词必须用复数.如：
The police are searching for the thief.
3）单、复数同形的名词主语时,谓语动词应根据意义决定单、复数.如：
A sheep is over there.
Some sheep are over there.
4）名词所有格之后的名词被省略,这种情况一般只指商店、工厂、住宅等,作主语时,动词一般用单数.如：
The doctor’s is across the street.
My uncle’s is not far from here.
常见的省略名词有：the baker’s, the barber’s, the carpenter’s, the Zhang’s等.
表示店铺的名词,一般作集体名词看待,但用作主语时,谓语动词往往用复数.如：
Richardson’s have a lot of goods to sell.
5）当名词词组中心词为表示度量、距离、金额、时间、书名等复数名词时,往往可以根据意义一致的原则,把这些复数名词看作一个整体,谓语用单数形式.如：
Three years has passed since then.
6）不定代词each, every, no所修饰的名词即使以and或逗号连接成多主语时,谓语动词仍用单数形式.如：
Each boy and each girl wants to go to the cinema.
7）如果主语有more than one…或many a…构成,尽管从意义上看是复数内容,但它的谓语动词仍用单数形式.如：
More than one student has read the book.
Many a girl has been there.
但是,“more +复数名词+than one”结构之后,谓语动词一般多用复数形式.如：
More members than one are against your plan.
8）一些有两个部分构成的名词表示衣物或工具作主语时,谓语动词通常用复数形式,例如：glasses, clothes, trousers, shoes, compasses, chopsticks, scissors等.但如果主语用“a kind of, a pair of , a series of等加名词”构成时,谓语动词一般用单数形式.如：
A pair of shoes was on the desk.
9）this kind of book =a book of this kind（这种书）,其谓语动词用单数；短语this kind of men =men of this kind =these kind of men(口语)（这一类人）,但this kind of men的谓语动词用单数,men of this kind和these kind of men的谓语动词用复数,all kinds of后跟复数名词,谓语动词用复数形式.如：
This kind of men is dangerous.
Men of this kind are dangerous.
10）复数形式的单、复数同形名词作主语时,按意义一致原则,作用单数意义时,谓语用单数,反之,谓语用复数.这类名词有：means（方法）,works（工厂）,species（种类）,Chinese,Japanese等.如：
The (This) glass works was set up in 1980. (这家玻璃厂建于1980年.)
The（These）glass works are near the railway station. （这些玻璃厂在火车站附近.）
当它们前面有a, such a , this, that修饰时,谓语用单数；有all, such, these, those修饰时,谓语用复数,但means, no means, the means等词前没有以上修饰词时,可用作单数,也可用作复数.
11）如果名词词组中心词是all,most, half, rest等词语,所指的复数意义,谓语动词用复数形式；反之,用单数.如：
All of my classmates like music.
All of the water is gone.
12)在主谓倒装的句子中,谓语动词的数应与其后的主语一致.如：
Between the two windows hangs a picture.
2．由连接词连接的名词作主语
1） 用and或both…and连接并列主语,谓语动词通常用复数形式.如：
Plastics and rubber never rot.
Walking and riding are good exercises.
但是,并列主语如果指的是同一个人、同一事物或同一概念时,谓语动词用单数形式,这时and后面的名词没有冠词.如：
Truth and honesty is the best policy.
The girl’s teacher and friend is a young doctor.
To love and to be loved is great happiness.
Going to bed early and getting up early is a good habit.
A knife and fork is on the table.
2）当主语后面跟有as well as, as much as, no less than, along with, with, like, rather than, together with, but, except, besides, including, in addition to等引导的词组时,其谓语动词的单、复数而定.如：
The teacher as well as the students was reading in the library.
3）以or, either…or, neither…nor, not only…but also等连接的名词（代词）作主语时,谓语动词的单复数应根据就近一致的原则.如：
Tom or his brothers are waiting in the room.
Either you or he is to go.
3．代词作主语
1）名词性物主代词作主语时,既可以用作单数,也可以用作复数,这取决于它所代替的是单数还是复数.如：
Ours (Our Party) is a great party.
Your shoes are black, and mine(=my shoes) are brown.
2）such, the same起指示代词作用时,应根据其所指的内容来决定单、复数.如：
Such is our plan. Such are his words.
3）关系代词who, that, which等在定语从句中作主语时,其谓语动词的数应与句中先行词的数一致.如：
Those who want to go please put up your hands.
Some of the energy that is used by man comes from the sun.
4）疑问代词who, what, which作主语时,谓语动词可根据说话人所要表达的意思决定单、复数.如：
Who lives next door ? It is Xiao Liu.
Who live next door ? It is Zhang and Liu.
What produce(s) heat ?
5）不定代词any, either, neither, none, all some, more等作主语时,有以下两种情况：
单独作主语时,视其在文中的意义,动词用单数或复数形式,例如：
Now all has been changed. All are present.
either, neither单独作主语时,谓语通常用单数.
但后接of时,若of的宾语为不可数名词,动词当然用单数形式,若of的宾语为复数名词或代词时,动词可以是单数,也可以是复数,在正式文体中,单数形式的动词更常用.如：
Do(es) any of you know his address ?
None of them has(have)seen the film.
4．分数、量词作主语
1）“分数或百分数+名词”构成的短语以及由“a lot of, lots of plenty of, a large quantity of, a heap of, heaps of, half of +名词”构成的短语作主语时,其谓语动词要与短语中of后面的名词的数保持一致,这是因为短语中后面的名词是中心词,而短语中前面的量词是修饰语,例如：
Lots of damage was caused by fire.
About three-fourths of the earth’s surface is covered with water. Three-fifths of the workers here are women.
和这种情况类似的还有“a number of+名词复数”,但是,“the number of +名词”的中心词却是number, 试比较：
A number of students have gone home.
The number of pages in this book is two hundred. 注意：(large)quantities of修饰可数或不可数名词,其短语作主语时,谓语动词一般用复数,例如：
Quantities of food(nuts) were on the table.
短语in quantity, in large quantities意为“大量”；in small quantities意为“少量”.
2）a great deal of , a large amount of修饰不可数名词,其短语作主语时,谓语动词通常用单数；large amounts of修饰不可数名词,其短语作主语时,谓语动词通常用复数,例如：
A large amount of(A great deal of)damage was done in a very short time.
Large amounts of money were spent on the bridge.
3）表示数量的one and a half后,名词要用复数形式,但是其短语作主语时,谓语动词用单数形式,例如：
One and a half bananas is left on the table.
4）half of, (a) part of修饰可数名词单数及不可数名词时,谓语动词用单数,修饰可数名词复数时,谓语动词用复数.
．名词化的形容词作主语
如果主语由“the+形容词（或过去分词）”结构担任时,谓语通常用复数,这类词有：the brave, the poor, the rich, the blind, the young, the old, the sick, the dead, the deaf and dumb, the oppressed, the injured, the wounded, the unemployed等；但也有少数的过去分词与定冠词连用时指个别,则用单数.如：
The blind study in special schools.
The departed was a well-known engineer.
这类形容词或分词如果要表示个体时,就要与名词man, person或表示人的单数连和,如：an old man, a rich person, the(a)wounded soldier
6．从句作主语
）由what引导的主语从句,谓语动词通常用单数,但所指的具体内容是复数意义时,谓语动词一般用复数形式,例如： What we need is more time.
What we need are doctors.
2）在“one of+复数名词++who/that/which”引导的从句结构中,关系代词who/that/which的先行词是靠近它的复数名词而不是one,因此,从句中的动词应该是复数形式.如：
This is one of the most interesting stories that have been told.
但是当one之前有the only等修饰语时,关系代词的先行词是one,而不是靠近它的复数名词,因此从句的动词应是单数形式.如：
She was the only one of the girls who was late.