They have already had it and carrier of it with asymptotic and never knew or if they catch after rains peoples systems are low. In immune systems that is the natural fighter that cross the blood and brain. Barrier if low they can be prone to catching it as well.
But the answers provided im not seeing the real answer as in they put the problem that caused a. Disease in a vaccine only so much of it and add antidote example flu shot . It attacks some people immune system and they get sick because of injecting it into them but the belief is of catching it after I don’t believe I believe either your body can handle it or it does not and rejects it in the blood brain barrier so if recieved then you will get sick after getting the immunization
The trees give off oxygen for the fox to breath
Eutrophication of water bodies like lake, pond, shallow stretches of river, etc. is the phenomenon where excess growth of vegetation on the surface of the water takes place. This excess growth results in the clouding of the water, depletion of dissolved oxygen in water, and the death of aquatic organisms. The primary reason for the cause of eutrophication is the presence of nutrients in excess amounts in the water. The nutrients B. come from fertilizer and sewage runoff.
There are lots of animals that do this and they are classified as herbivores.
Answer:
Compound is a pure substance which is made from atoms of different elements combined together in a fixed ratio by mass.It can be decomposed into simpler constituents using chemical reactions. Example: water 
Physical property is defined as the property of a substance which becomes evident during physical changes. Water is liquid at room temperature whereas hydrogen and oxygen are gases at room temperature.
Chemical property is defined as the property of a substance which becomes evident during chemical changes. Water reacts with metals to form bases, hydrogen reacts with metals to form hydrides and oxygen reacts with metals to form oxides.
