A, of, water, here's, for, glass, you (.)

A, of, water, here's, for, glass, you (.)

Here's a glass of water for you.
I want to know a glass of water
If you remove of, it means that two nouns are together. What is the effect of translation? A "glass water"? Obviously not. Therefore, you must add of as a preposition in the middle
That's what English says. There's no reason. In fact, this can be seen as a fixed usage, do not use Chinese thinking to think about learning English!
Fixed collocation
Dirichlet function
Dirichlet function
{1, X is a rational number;
D(x)=｛
0, X is an irrational number
How to add "ing" to the present continuous tense in English?
1) Generally, add - ing. Go --- going stand --- standing 2) after the original verb form, remove E and add - ing. If the verb is a monosyllabic word with closed syllable, or a polysyllabic word with stressed closed syllable, and there is only one consonant at the end, the consonant should be written in double
Add is before, and then ing after the verb
He goes to work
He is going to work
be(is,are,were,was) + do +ing
The most easy thing for beginners to forget is to add the linking verb "be" in front of them. Be changes according to different tenses and persons.
Why are Dirichlet functions discontinuous everywhere?
Why is Dirichlet function discontinuous everywhere? Since real numbers are continuous and rational numbers are discontinuous, is the irrational number between two adjacent rational numbers not continuous? What's wrong with this idea?
Dirichlet function is a discontinuous function defined in the range of real numbers. When the independent variable is a rational number, and the independent variable is an irrational number, the image of Dirichlet function is axisymmetric about the axis, and it is an even function. It is discontinuous, and there is no limit everywhere
The present continuous tense: the expressive structure of declarative sentence, general question, special question and sentence
By the way, the word order formula of declarative sentence, general question sentence and special question sentence, and the three kinds of negation of must are discussed
The word order of declarative sentence: the most basic structure is subject + predicate + object
General questions: put be / modal verb / auxiliary verb at the beginning of the sentence
Special questions: special questions + general questions
The negation of must: mustn't, needn't, don't have to
Modal verbs have certain meanings, but they can't be used as predicates alone. They should be used together with action verbs to form predicates. They can also indicate the negation, question or tense difference of sentences. Common modal verbs are: can, may, must, need, should, etc
Expressive ability
Rose can speak now, but she could't a week ago
Be able to also means ability. It differs from can as follows:
1) But can only be used in the simple present tense and the simple past tense. Be able to can be used in any tense
She could / was able to eat four pieces of bread when she was young.
They will be able to finish the drawing soon.
2) This is the first time that we have been able to do something in the past
She was weak, but was able to finish the task last night.
When can (could) is used with the second person in interrogative sentences, it means asking for the other party's opinions or making a request, indicating a euphemistic mood
-Could you lend me your pen?
-Yes, I can.
Express permission
In general, may / may, can / could are used to express permission, and they are often interchangeable. The mood of May and could is more euphemistic. Special attention should be paid to: only may and can be used to give a direct answer to the questions beginning with may and could
-Might/Could I borrow your book?
-Yes, you may/can.
Necessary, necessary
Both must and have to have a "must", which are interchangeable in general
But they have the following differences:
1) Must is the speaker's subjective opinion; have to is the objective need
I must have a talk with him.
He has to give up smoking because of badly cough.
2) The negative mustn't means "no, you can't do it"; don't have to means "don't have to"
You mustn’t hit her.
You don’t have to explain it to me if you dislike the job.
Note: the modal verbs for speculation include must, should, out to and can, could, may, might
"Must" is used only in affirmative sentences, not in negative or interrogative sentences
1) To infer the present action, use the original form of "must + verb"
You must lose in the mountain.
2) You speak for 4 hours, you must be thirsty
In affirmative sentences, we use may (might) + the original form of the verb to infer that we are not sure about the present or the future, which is less likely than May; we use may (might) have + the past participle to infer that we are not sure about the past
The package might come tomorrow.
They may have killed the enemies.
3. In the interrogative sentence, we use can (could) to infer the present +Can (could) be used to express doubt about the past In negative sentences, can't + is used to infer the present and can't (could't) have + is used to infer the past
It can’t be John. He has gone to UK.
4. The dual identity of need
Need can be used as both modal and notional verbs
One seventh minus two fifths, (using junior high school calculation method) we just learned my rational number plus points, weight loss, and mixed operation
1/7-2/5=5/35-14/35=（5-14）/35=-9/35
10 special questions in the present continuous tense and answer them
What are you doing now?I am watching TV.What is he doing?He is reading a newspaper,Where is she going?She is going to the supermarket.What are they doing?They are playing basketball.Why is he staying ...
What are you doing? I am doing sth
The product of two rational numbers is 1. Given that one number is - 15 / 7, what is the other number
Just look for me. I'm very good at math
The present progressive general question structure
Be right
Be + subject + doing + sth
Advance the copula and change the end into a question mark
For example: you are doing your home
Are you doing your home?
what are you doing now?
are you watching TV?
Interrogative words, be, subject, doing and things