Выражения: 1) 1-sin²a/cos²a 2) (1+tg²a)•cos²a-sin²a 3) (ctg²a+1)•sin²a-cos²a

1) =(sin^2a+cos^2a)-1=1-1=0

1. If a burglar breaks into your house, always hand over your valuables.

2. I ran into an old friend at the supermarket yesterday.

3. We ran out of milk, so can you buy some when you're at the supermarket?

4. Hand your car keys over.

5. I saw two policemen running after a robber.

6. Keep your mobile phones swithed off at night.

1. Если в ваш дом вломится грабитель, всегда отдавайте ценные вещи.

2. Вчера в супермаркете я столкнулся со старым другом.

3. У нас кончилось молоко, так что можешь купить его, когда будешь в супермаркете?

4. Отдай свои ключи от машины.

5. Я видел двух полицейских, бегущих за грабителем.

6. Держите свои мобильные телефоны выключенными на ночь.

4 ACTIVATE Follow the steps in the writing

guide

O WRITING GUIDE

A TASK

Write an email to Beth about your interests.

B THINK AND PLAN

1 What's your name and age?

2 Where are you from and what's your school?

3. How many people are in your class?

4 Do you do sports as a class?

5 What sports do you and the other people in

your class like?

6 What other lessons do you enjoy? Why?

7 What questions have you got for Beth?

C WRITE

Write your email. Use and, or and but and the

key phrases

Paragraph 1. Introduction

My name's...

Paragraph 2: Hobbies and interests

I'm really into ...

Paragraph 3: Questions

What about you?

D CHECK

and, or and but

• spelling

Объяснение: