Ozone is a gas in the atmosphere that protects everything living on the Earth from harmful ultraviolet (or UV for short) rays from the Sun
Oral polio vaccine is highly effective and inexpensive (about US$0.10 per dose, or US$0.30 per child and its availability has bolstered efforts to eradicate polio. A study carried out in an isolated Eskimo village showed that antibodies produced from subclinical wild virus infection persisted for at least 40 years. Because the immune response to oral polio vaccine is very similar to natural polio infection, it is expected that oral polio vaccination provides similar lifelong immunity to the virus.
Contact immunity to polio can occur when attenuated poliovirus derived from the oral polio vaccine is excreted, and infects and indirectly vaccinates unvaccinated individuals.
It depends on the life stage that the star is in. Currently, in the mid-life stage, the sun is still fusing hydrogen into helium, so the maximum here is helium; however, far in the future when the star is nearing its final days, it can fuse atoms into elements as heavy as iron and nickel.
Answer:
for 16 it is heart.
Explanation:
for 17 it is kidney to bladder
Calcium is a chemical element with symbol Ca and atomic number 20. Calcium is a soft gray Group 2 alkaline earth metal, fifth-most-abundant element by mass in the Earth's crust. The ion Ca2+ is also the fifth-most-abundant dissolved ion in seawater by both molarity and mass, after sodium, chloride, magnesium, and sulfate.[5] Free calcium metal is too reactive to occur in nature. Calcium is produced in supernova nucleosynthesis.
