Answer:
More than 7000 chemicals are present in tobacco smoke.
Explanation:
In these 7000 chemicals, 250 are harmful to the human body such as carbonmonoxide, ammonia and hydrogen cyanide etc. There are some chemicals that are found in tobacco smoke which causes cancer disease in human. About 69 chemicals out of 250 are present in tobacco smoke that causes cancer disease. So its consumption is dangerous for health.
Vector: anything that transmits a disease.
Malaria vectors can include mosquitos, ticks, and other blood sucking insects.
P.S.: Hope I Helped :)
<em>I </em><em>Don't </em><em>No</em><em> </em><em>if </em><em>you </em><em>have </em><em>any </em><em>questions </em>
ANSWER:
Its because mother nature tells us herself!
its just like predicting when rhinos will go instinct:
imagine people killing 2 rhinos a week or every two weeks and theres only 500-1000, you can predict that in prob 3-5 years they'll go instinct
so its just like that and they have much higher technology now that it'll just give them the answer without putting much effort into it.
~batmans wife dun dun dun....