Answer:
<em> A. 38%</em>
Explanation:
Percentage increase in carbon dioxide concentration = (Increase in concentration of carbon dioxide/initial concentration)×100
P = (C₂-C₁/C₁)×100...................... Equation 1
Where P = percentage increase in the concentration of carbon dioxide from 1970 to 2007, C₁ = The atmospheric concentration of carbon dioxide in 1970, C₂ = The atmospheric concentration of carbon dioxide in 2007.
<em>Given: C₁ = 278 ppm, C₂ = 383 ppm.</em>
Substituting these values into equation 1
<em>P = [(383-278)/278]×100</em>
<em> P = (105/278)×100</em>
<em>P = 37.7%</em>
<em>P ≈ 38%</em>
<em>Thus the approximate percentage increase in carbon dioxide concentration from 1790 to 2007 is 38%</em>
<em>The right option is A. 38%</em>
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Answer:
C. Using cell phones while driving increases the likelihood of crashing.
Explanation:
As the statement mentions, science and technology have improved our livelihoods significantly. However, they have also brought numerous disadvantages.
The development of cell phones has made our lives easier. In contrast to [only] 50 years ago, <u>communication has become extremely easy and fast</u>. We are able to share our location with someone in less than a minute and to call a family member even if we are thousands of kilometers away.
However, people are now overusing these equipments, which has led to an increase of road accidents due to the lack of concentration while driving. For instance, according to statistics, in 2018 over 4,000 people died in car crashes because they were using cell phones while driving.
Therefore, <u>a negative effect of using cell phones would be C. using cell phones while driving increases the likelihood of crashing.</u>
Answer:
a dynamic equilibrium existing between members of any relatively stable natural community and being the resultant of all the effects (as in food chains, parasitism, or pollination) of the constituent organisms on one another. Hope this helps!
The answer is <span>The respiratory system supplies the oxygen that the cardiovascular system transports to the different cells for the production of energy.
When air enters the lungs (part of the respiratory system), it passes all way to the alveoli, the smallest functional units of the lung. There, oxygen from the air enters the capillaries, the smallest blood vessels, next to the alveoli. Once in the blood stream, the cardiovascular system transports oxygen to different cells where it is used for the energy production.</span>
Answer:
Until recent history,extinctions have always happened gradually and on a small scale.
Explanation:
Extinction occur when environmental factors like natural disaster,habitat fragmentation,over exploitation,global change don't favor the survival of species thus gradually leads to extinction of species.
Some times human activity becomes the major problem for extinction.More over,poor reproduction,decline in population number and genetic inbreeding also leads to extinction.
99% of all species that exist on earth become disappeared.
Evolution leas to speciation which leas to formation of new species but species become extinct when they are unable to survive against competition.
