Answer:
cells
Explanation:
All organisms are composed of one or more cells
 
        
             
        
        
        
Answer:
hey mate this is your answer
Explanation:Cancer is unchecked cell growth. Mutations in genes can cause cancer by accelerating cell division rates or inhibiting normal controls on the system, such as cell cycle arrest or programmed cell death. As a mass of cancerous cells grows, it can develop into a tumor.
 
        
             
        
        
        
Lead emission since early 1980s have DECREASE DUE TO LEAD FREE GASOLINE. 
Lead is a natural occurring element that is found in small quantity in rocks and soils. Lead emission is an important environmental health issue because a very small quantity of lead can cause adverse effects on the nervous system of unborn babies and young children. Because of this, the government took all necessary measures to ensure that its emission was drastically reduced.
        
             
        
        
        
Evidence for evolution, in other words evidence of common descent, include fossils, which have shown a (fairly) steady change in morphology over time for some species. An example would be horse hooves: we have fossils that show when they were still three toed, then two toed, then one toe in our present day horses. Another piece of evidence is vestigial organs. An example of vestigial organs is wings in some flightless birds, such as the kiwi. Their ancestors used it in order to fly across the marine barrier into New Zealand, but natural selection and random genetic drift made them quickly lose the ability to fly. Nonetheless, they still have their wings, however small. It can be assumed that eventually, their wings would be reduced to small stubs fused to other nearby bones, as has been observed in their cousins.