سلام

امروز بيستمين روزيه كه داريم اين لغات را مي خوانيم تا حالا 106 تا لغت ياد گرفتيم . در زير، مجموع درسهاي يازدهم تا بيستم را مي نويسم كه يكبار دوره بشه و از فردا لغتهاي درس بيست و يكم را مي خوانيم.

Let's look at how it works the immune system protects your body in three different ways. First, it creates a barrier that prevents bacteria and viruses from entering your body. Then if a bacteria or virus does enter your body, your immune system finds it.

And finally, if the virus or bacteria start to hurt your body, your immune system destroys it .that means, even if you are feeling sick, your immune system is still working!

It is trying very hard to destroy the sick ness in your body.

So how does the immune system do all this?

Well, let's start by learning about the different parts of the immune system. There are parts of the immune system that you can see. And parts you can not see. The skin acts as a barrier between germs and your body. The skin is strong enough to resist many different kinds of germs. Your skin also releases a special substance.

It kills bacteria on the surface of your skin. Your eyes, ears, nose and mouth also contain parts of your immune system .There are special fluids in each of these parts of your body. The fluids kill germs and bacteria before they can enter your body.