Climate change refers to significant changes in global temperature, precipitation, wind patterns and other measures of climate that occur over several decades or longer.
The seas are rising. The foods we eat and take for granted are threatened. Ocean acidification is increasing. Ecosystems are changing, and for some, that could spell the end of certain regions the way we have known them. And while some species are adapting, for others, it’s not that easy.
Evidence suggests many of these extreme climate changes are connected to rising levels of carbon dioxide and other greenhouse gases in the Earth’s atmosphere — more often than not, the result of human activities.
Climate change, therefore, is a change in the typical or average weather of a region or city. This could be a change in a region's average annual rainfall, for example. Or it could be a change in a city's average temperature for a given month or season. Climate change is also a change in Earth's overall climate.
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Answer:
Option a
Explanation:
The front of the white paper packet of the OSL dosimeters may be color-coded to facilitate correct usage and placement of the badge on the body of occupationally exposed personnel.
OSL dosimeters are recently developed and are of high quality than thermoluminescent dosimeters.  It is used to monitor patients health status. Furthermore, it is very sensitive to any change or drop in reading. it give accurate readings even at 1 mrem for both gamma ray photos and X-rays.
Reference: Yukihara, E. G., et al. "Evaluation of optically stimulated luminescence (OSL) dosimeters for passive dosimetry of high‐energy photon and electron beams in radiotherapy." Medical physics 35.1 (2008): 260-269.
 
        
             
        
        
        
1. Having a sickle cell anemia crisis is a severe condition of reduced red blood cell count.
 2. Having sickled red blood cells lead to the symptoms like having pain in the chest and the throbbing of her leg.
 3. A person having sickle cell anemia is mostly tired due to reduction in red blood cells, so they cannot do any work with their bodies. There would difference in the personal appearances like yellow eye and skin looks pale and the skeletal system become weak too. There is trouble with breath too. 
 4. The symptoms are as follows like the patient fall in to anemia condition, urine is dark in color, eyes are yellow, and person looks pale and the body experiences frequent pain and delay in the body growth.
 5. Hydroxyurea is the medication used here. The pros of this are the frequent body pains reduces and reduction in need of blood transfusion. the cons are increase of infection and this particular drug may cause tumors and leukemia.
        
             
        
        
        
The answer is cnidaria
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Explanation:
1.The Moon has phases because it orbits Earth, which causes the portion we see illuminated to change. The Moon takes 27.3 days to orbit Earth, but the lunar phase cycle (from new Moon to new Moon) is 29.5 days. The Moon spends the extra 2.2 days "catching up" because Earth travels about 45 million miles around the Sun during the time the Moon completes one orbit around Earth.
2.
An eclipse is the result of the total or partial masking of a celestial body by another along an observer's line of sight. Solar eclipses result from the Moon blocking the Sun relative to the Earth; thus Earth, Moon and Sun all lie on a line. Lunar eclipses work the same way in a different order: Moon, Earth and Sun all on a line. In this case the Earth's shadow hides the Moon from view.Lunar and solar eclipses occur with about equal frequency. Lunar eclipses are more widely visible because Earth casts a much larger shadow on the Moon during a lunar eclipse than the Moon casts on Earth during a solar eclipse. As a result, you are more likely to see a lunar eclipse than a solar eclipse.
3.Why Do We have Seasons?
 
As the earth spins on its axis, producing night and day, it also moves about the sun in an elliptical (elongated circle) orbit that requires about 365 1/4 days to complete. The earth's spin axis is tilted with respect to its orbital plane. This is what causes the seasons. When the earth's axis points towards the sun, it is summer for that hemisphere. When the earth's axis points away, winter can be expected. Since the tilt of the axis is 23 1/2 degrees, the North Pole never points directly at the Sun, but on the summer solstice it points as close as it can, and on the winter solstice as far as it can.
Why Do the Seasons Change on Earth?
Two things cause the seasons to change. First, the Earth moves around the Sun. Second, the Earth has a tilted axis of rotation.
The Earth spins around an axis. This imaginary line extends from the South Pole to the North Pole. But the Earth’s axis is not vertical. It’s actually tilted at an angle of 23.5°. The planet is always tilted in the same direction as it orbits the Sun.