Certain animals know without analysis the difference between

a的用法？
a的一个用法是这样的，
某一个 等于 a certain，用于专有名词前，这个 等于 a certain这个地方没看懂，谁来解释下

英语作业大神帮忙
Normally a student must attend a certain number of courses in order to graduate, and each course which he attends gives him a credit which he may count towards a degree. In many American universities the total work for a degree consists of thirty-six courses each lasting for one semester. A typical course consists of three classes per week for fifteen weeks. While attending a university a student will probably attend four or five courses during each semester. Normally a student would expect to take four years attending two semesters each year. It is possible to spread the period of work for the degree over a longer period. It is also possible for a student to move between one university and another during his degree course, though this is not in fact done as a regular practice.
For every course that he follows a student is given a grade, which is recorded, and the record is available for the student to show to prospective employers. All this imposes a constant pressure and strain of work, but in spite of this some students still find time for great activity in student affairs. Elections to positions in student organizations arouse much enthusiasm. The effective work of maintaining discipline is usually performed by students who advise the academic authorities. Any student who is thought to have broken the rules, for example, by cheating has to appear before a student court. With the enormous numbers of students, the operation of the system does involve a certain amount of activity. A student who has held one of these positions of authority is much respected and it will be of benefit to him later in his career.

6.Normally a student would at least attend ________ classes each week.
A) 10 B) 12 C) 15 D) 20
7. According to the first paragraph an American student is allowed ________.
A) to live in a different university
B) to take a particular course in a different university
C) to live at home and drive to classes
D) to get two degrees from two different universities
8.The pressure of future career is felt by American university students mostly because of the r ecord of their ________.
A) academic performance B) social activities
C) personal conduct D) leadership abilities

more problems like those are certain to arise..像这样的问题肯定还会出现,能改为 .more problems
would arise certainly...

英语翻译
you can declare excess valuation on certain baggage at the airport,additional fees well apply.

托福改错题
certain types of 1(computers) work 2(properly) only in 3(environments) with 4(precisely controlled) temperatures.
是应该改4吗?
可是controlled是动词把 precisely是副词把.这样的搭配应该是对的把?

英语翻译
In a certain game,each token has one of three possible values:1 point,5 points,or 10 points.How many different combinations of these token values are worth a total of 17 points?
(A) Two (B) Three (C) Four (D) Five (E) Six

please hang it on the wall.______[certain,all right]
为什么不用CERTAIN呢

It is certain that he will ______ his business to his son when he gets old.
a、take over
b、think over
c、hand over
d、go over

有关形式主语
有些句子里可不可以不用形式主语,比如这个
It seemed certain that their plane would crash
应该怎么改

On Father's day I'm certain to give my father a present.
改为同义句：On Father's day I'm ( ) ( ) give my father a present.
每空填一个单词

Scientists have discoverd that the leaves of acertain type of (plant) contain a kind of medicine.
句中的plant为什么不能用plants呢?

Such certainty is beautiful.but uncertainty is more beautiful still.麻烦翻译下!

In English, certain nouns are spelt with _____capital letter at _____ beginning of the word; for example, names of places, such as the United States of America. A．a; the B．the; the C．a; a D．the; a

After certain observations,the scientist ___ that there might be other forms of life in outer space
[A] expressed [B] concluded [C] regarded [D] inspected
And reason,please.Thanks.

right exact certain的区别
When the teachers asks you a question,he expects a(an)_____an answer
Aright.B.fast.C.exact.D.certain

it is certain that an offer si well worth ----- 选WHAT,讲reason,3Q!
A being thought about B toshink
c thingking about D to think of

为什么不选however
I’m certain David’s told you his business troubles.____,it’s no secret that he owes a lot of money to the bank.
A.However B.Anyway C.Therefore D.Though

求翻译the anthropologists could be certain of how big a band the victims belong to
the anthropologists could be certain of how big a band the victims belong to 这句怎么翻译,可不可以将这句结构分解下? 谢谢!

That the earth goes around the sun is certain.本句中That引导 ______从句.

the decision to shop in a certain supermarkde and the decision to drop out of college according 是

求翻译一个句子
The fact did not escape me that a certain proportion of my peers showed what amounted to an honest passion for their duties.
我主要是想知道这里的amount to怎么翻译才合适.
另外,这个句子的句子成分分析不出来.

一个英语完成句子...
——————（我们团结一致）at present.It is certain that we can deal with every challenge.用with和hold来完成.

英语填空
1.I think she is a _(feel certain of his/her own ability)person. 2. Eddie is _(the opposite of thinner)than before.

英语翻译
After a certain time period,the usage.
After a certain time period,the usage bit is set to 0.
抱歉没打全

the rate of a certain reaction is directly proportional to the square of the concentration of chemical A present and inversely proportional to the concentration of chemical B present.if the concentration of chemical B is increased bu 100 percent,which of the following is closest to the percent change in the concentration of chemical A required to keep the reaction rate unchanged?

The idea,once ____ to the article,is certain to make it more persuasive.A adding B added

英语翻译
（1）'Tis（it is） certain I shall never recover if I am to be so long separate from you:yet with all this devotion to you I cannot persuade myself into any confidence of you.主要是后半句
（2）Ask yourself how many unhappy hours Keats has caused you in Loneliness.
（3）Even if you did not love me I could not help an entire devotion to you:how much more deeply then must I feel for you knowing you love me.

A certain number is greater than
the reciprocal of a natural number is at most 1

There are certain times when you can make a wish,too .For example. when you cut a birthday cake
thank

求英语高手指点.
1 句子改错
Dispite much research ,there are still certain elements in the life cycle of the insect that
is not fully undertood. (在学习主谓一致后的练习题,估计是主谓一致的问题,可是不知道错在哪里）
2 单选题.he is from ( )and i am from( )
A , a worker family a peasant family B, a worker family peasant family
感激不尽

It was a question of making sure that certain needs were addressed ,notably in the pensions area.翻译,并语法解释.

一道GMAT数学题
This year Henry will save a certain amount of his
income,and he will spend the rest.Next year Henry
will have no income,but for each dollar that he saves
this year,he will have 1 + r dollars available to spend.
In terms of r,what fraction of his income should Henry
save this year so that next year the amount he has
available to spend will be equal to half the amount that
he spends this year?
for each dollar that he saves
this year,he will have 1 + r dollars available to spend.
完全不懂这句话……求解!

英语翻译
1.Make certain ring protectors,or shrouds,are secured around operator's RUN botton
2.Make certain controls are being used properly and in a safe manner.
3.Check for presence of any unprotected wires.
4.Make certain all electrical covers are in place.
5.Check main drive motor mounting bolts and motor bracket mounting bolts for tightness;tighten if necessary.
6.Remove any accumulated dirt,oil or grease from motor frames.Cauion:Do not allow cleaning solution to drip inside motors.

——That's a beautiful coat in the window ——It certain ly is,if I had the money,____buy it.
A I'll
B I may
C I'd
D I must

有一个英语长难句问题~
It indicates the dawning of certain sensibilities,perspectives,and standards without which arts programs are mockeries of everything the arts stand for.
without后面那个是什么成分?
有人说是定语从句,但我觉得如果是定语从句的话后面怎么会是个完整的句子呢?关系代词不是要在从句里做成分么?
如果觉得没有上下文不好理解的话,请把它复制到百度里然后看一下原文,是SAT的阅读.

阅读题一篇
Task 1
If someone asks if you are free at a certain time and invites you to an event ,you are not required to commit yourself until you know what the invitation is for.For example ,if you say that you’re free and the invitation turns out to be something you’d hate to do (a trip to a local sight you’ve seen ten times),then you will be in a position to take back your acceptance or invent an excuse later.If this happens,tell the person who invites you that you have to check and that you’ll tell him or her later.If this happens,tell the person who invites you that you have to check and that you ’ll tell him or her later.If an invitation must be refused ,most people expect a reason.The following sequence would be appropriate :apology,reason for refusal,thanks for the invitation.
When someone asks you to his or her home,it is very clear who is the guest and who is the host,but invitations to restaurants for lunch,dinner,coffee,a drink,etc.,sometimes present problems,and the customs vary in different parts of the United States.
In many instances it is the inviter who pays,as one would expect,but in some instances each one pays his or her own check:You “go Dutch.” This is often the case with friends in informal situations,such as “Let’s go and get a beer” or “Want a cup of coffee?”
1.Which of the following sequence would be appropriate?
A apology,reason for refusal,thanks for the invitation
B.commitment,reason for refusal,thanks for the invitation
C.reason for refusal,thanks for the invitation,apology
D.commitment ,thanks for the invitation ,reason for refusal
2.What would you do if someone only invites you ,but doesn’t say what the invitation is for?
A.Give commitment directly .
B.Give commitment before you knew what the invitation is for.
C.Give commitment after you knew what the invitation is for.
D.Refuse directly.
3.When is a reason expected?
A.You are late for the invitation.
B.You refuse the invitation for some reason.
C.You accept the invitation after refusing it.
D.The invitation turns out to be something you’d hate to do.
4.What does “go Dutch” mean?
A.Each one pays his own check.
B.Go abroad for traveling.
C.Have a rest.
D.Spend little money.
5.Which of the following is true?
A.Host will pay for the bill if he invites other to restaurants.
B.You should keep your promise even though you don’t like the invitation.
C.You are required to commit before you know what the invitation is for.
D.Customs vary in United States as for who will pay the bill in restaurants.

_______to take this adventure course will certain learn a lot of useful skills.A.Brave enough students B.Enough brave students C.Students brave enough D.Students enough brave 个人觉得选B,但答案是C.纠结.....

100分求一道数学题,
After t years the population of a certain town is P(t) = 50+5t thousand people.A populationP has an associated CO2 level,C(P) = (根号下（P2 + 1）)/2.After 2 years,the rate at which CO2 level is changing with respect to t will be:答案是150/根号下3601 实在闹不明白为什么,
C(P) = (根号下（P2 + 1）)/2.P后面的2表示P的平方

英语翻译
1.Enron matched a certain proportion of each employee's 401 (k) contribution with company stock,so everyone was going to end up with some Enron in his or her portfolio; but that could be regarded as a freebie,since nothing comples a company to match employee contributions at all.
2.In Uncle Geoff's view,the greatness of England had risen and waned over the centuries in direct proportion to the use of natural manure in fertilizing the soil.