They discovered a vaccine to reduce illnesses, specifically Polio and Influenza. The work of Salk and Sabin has almost eradicated what was once a deadly disesase ( polio) . For example, there were 350,000 deaths related to poliovirus across the world in 1988 and they reduced to 22 in 2017. Also, their work has saved millions of lives from polio induced paralysis
Answer:
B. blocks 2 & 3.
Explanation:
Block 1 has equal & opposite forces acting on it.
Block 2 has 5N on one side, 3N on the other. It will move in the direction the 5N of force is pushing.
Block 3 has no opposing force.
Answer:
Molecules speed up
Explanation:
This is caused because of the temperature increasing. The temperature increase is telling us that the thermal energy of the reaction is increasing. When the energy is increased molecules increase their speed, because they have more energy in them
To solve this problem it is necessary to use the concepts related to Snell's law.
Snell's law establishes that reflection is subject to
Where,
Angle between the normal surface at the point of contact
n = Indices of refraction for corresponding media
The total internal reflection would then be given by
Therefore the 
would be equal to
Therefore the largest value of the angle α is 30.27°
About 80% of the earth's volume is made of mantle.
<span>The </span>mantle<span> is a layer inside a </span>terrestrial planet<span> and some other </span>rocky planetary bodies<span>. For a mantle to form, the planetary body must be large enough to have undergone the process of </span>planetary differentiation<span> by </span>density<span>. The mantle lies between the </span>core<span> below and the </span>crust<span> above. The terrestrial planets (</span>Earth<span>, </span>Venus<span>, </span>Mars<span> and </span>Mercury<span>), the </span>Moon<span>, two of </span>Jupiter<span>'s </span>moons<span> (</span>Io<span> and </span>Europa<span>) and the </span>asteroid Vesta<span> each have a mantle made of </span>silicate<span> rock.</span><span>Interpretation of spacecraft data suggests that at least two other moons of Jupiter (</span>Ganymede<span> and </span>Callisto<span>), as well as </span>Titan<span> and </span>Triton<span> each have a mantle made of </span>ice<span> or other </span>solid volatile<span> substances </span>up of Mantle
Hope this helped.
