How skin and mucus membrane act as barriers for infections?

Find whether the following sentences are true or false.If false Correct the statement. Heart forms an effective barrier against infection by microbes and pathogens.

Assertion: River, lake and canyon found in between the vegetation act as a natural fire break. Reason:Rivers and lakes which lack vegetation acts as a barrier in spreading the fire.

Read the given statements carefully. (i) Innate immunity is a specific type of defence, that is present at the time of birth. (ii) Malignant malaria is caused by Plasmodium falciparum. (iii) Malaria could be confirmed by Widal test. (iv) Active immunity is slow and takes time to give its full effective response. (v) Saliva in the mouth acts as physiological barrier for pathogens. Which of the above statements are correct ?

Assertion : Mucous membrane immobilises the micro-organisms in the body. Reason : Microoganisms and dust particles entering the respiratory tract are trapped in the mucus.

Assertion: Skin ofleech is kept moist and slimy. Reason : It is due to secretion of mucus which also prevents it from drying

How does water act as a good solvent?