когда употребляется артикль the а когда a?

help me?

Alice:Yes,of course.I like this pudding.What do we need for it?

Mrs Wilson:Just some oil,flour,eggs and milk.

Alice How ... flour do we need?

Mrs Wilson:A cup of flour.Get some eggs and milk from the fridge.

Allice:Oh!How ... eggs shall Iget out?There's ... milk and ... eggs in the fridge.

Mrs Wilson:We need 3 eggs and a cup of milk for the pudding.

Alice:Here you are.Anything else?Sugar?Salt?

Mrs Wilson:Some salt,please.There isn't any sugar in Yorkshire pudding.

Alice:How ... salt shall I get?

Mrs Wilson:Just ... .Hm.The batter is ready.Now let's cook them.

Say which of them are sports and which of them are games:
skiing, skating, football, rugby, boxing, rowing, horseracing, basketball, golf, volleyball, running, high jump, cricket, ice hockey, badminton, tennis, baseball

Change the sentences to indirect speech.
1)will you write the date, please!
The teacher told Tom............the date.
2)please come on time.
the teacher told the children............on time.
3)Don't make any sandwiches.
mothe told me............any sandwiches.
4)Do your homework!
mother told me............
5)Don't put on the coat.
mother told me........the coat.
6)Answer my question!
Mr Brown told Sam........question.
7)Don't ask me about it!
My sister told me.......... about it.
8)Don't take my book!
Jane told Jerry.........book.
9)Don't give me the cup!
Mrs Turnet told Mrs Harris...........the cup.
10)Don't sit on the desk!
The teacher told Nick............on the desk.

а)если перед существительнымми стоит указательное местоимение
б)с именами существительными
с)с имена существительными,после которых стоит количественное числительное
д)при указании на предмет существительным

Почему перед weather стоит определенный артикль the, ведь по правилу с weather употребляется нулевой артикль.

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