IV. Find mistakes in the sentences according to the text

1. In chemistry, immunity is the state of having sufficient biological defences to avoid infection, disease, or other unwanted biological invasion.

2.The non-specific components act either as barriers or as eliminators of wide range of pathogens irrespective of genetic specificity.

3.Microbes first encounter the cells, physical barriers that line our skin and mucous membranes.

4.The phagocytes express cell surface receptors that cannot bind.

5.Artificial immunity is often sub-divided into two major types depending on how the immunity was introduced.

6.Artificially acquired immunity occurs through contact with a disease causing agent.

7.Active immunity is acquired through transfer of antibodies or activated T-cells from an immune host.

8.Innate immunity is characterized by the cells involved; humoral immunity is the aspect of immunity that is mediated by secreted antibodies.

9.Humoral immunity is passive when the organism generates its own bodies.

10.T-cells aren’t stimulated and active when T cells come from another organism.

V. Retell the text

SSW 13

Grammar: Infinitive

1. Uses of the infinitive (with to): infinitive + to

I want to go to the party

I need to buy some new clothes

It’ll be important not to be late

Use to+ the infinitive after:

· Some verbs (want, need, would like, etc.).

· Adjectives

It isn’t easy to find a job. Nice to meet you.

The negative infinitive is not to+ verb

Try not to be late tomorrow.

2. Infinitive of purpose

A) Why did you go to the party?

B) To meet new people.= I went to the party to meet new people

· Use to + the infinitive to say why you do something.

I came to this school to learn English. NOT for learn English.

Verb + infinitive

- As it was late, we decided to take a taxi home.- They agreed to lend me some money when I told them the position I was in.

The negative is not to ...:

- We decided not to go out because of the weather.

After some verbs to…is not possible. For example,think and suggest

- Are you thinking of buying a car? ( not`thinking to buy')

- Tom suggested going to the cinema. (not `suggested to go')

Verb + object + infinitive

(a) Want ask expect wish should/would like hate advise recommend allow permit helpThese verbs are followed by to…( infinitive) The structure can be: verb + toor verb + object+ to

- I want to read this book immediately. = I'll do it myself.

- I want you to read this book immediately. = You'll do it.

- She would like to go to the concert. = She will do it herself.

- She would like me to go to the concert. = I will do it.

- We expect you to win.- She made me cry.- They want us to help them.

- The parents do not let the boy join his friends.- Would you like me to go now? I saw her enter the room.