Tubuh selalu kontak dengan lingkung

Tubuh selalu kontak dengan lingkungan yang banyak terdapat kuman-kuman. Kuman-kuman dapat masuk melalui udara pernapasan maupun makanan. Dalam hal ini tubuh memiliki sistem kekebalan untuk menghalangi dan bahkan membunuh kuman-kuman tersebut. Agar tidak merugikan tubuh. Sistem kekebalan pada tubuh dapat dibedakan menjadi dua, yaitu sebagai berikut :

Hasil (Inggris) 1:

The body is always in contact with the environment that many germs. Germs can enter through the respiratory air or food. In this case the body's immune system has to obstruct and even kill the germs. In order not to harm the body. The immune system in the body can be distinguished into two, namely the following:

Hasil (Inggris) 2:

The body is always in contact with the environment there is lots of germs. Germs can enter through the respiratory air and food. In this case the body has an immune system to deter and even kill germs. In order not to harm the body. The immune system in the body can be divided into two, namely as follows: