Give the real pills and placebo pills to both the girls and the boys.
A vaccine works by training the immune system to recognize and combat pathogens, either viruses or bacteria. To do this, certain molecules from the pathogen must be introduced into the body to trigger an immune response.
Answer:
They are the alkali metals, alkaline earth metals, transition metals, other metals, metalloids, non-metals, halogens, noble gases and rare earth elements.
The most biologically devastating oil spills in the marine environment are usually a result of the sinking of oil tankers.
An oil spill is a type of pollution that occurs when a liquid petroleum hydrocarbon is released into the environment, particularly the marine ecology.
Oil releases into the sea or coastal waterways are generally referred to as marine oil spills, however land-based spills are also possible.
Oil spills can result from crude oil discharges from tankers, sinking of oil tankers, offshore platforms, drilling rigs, and wells as well as refined petroleum products (like gasoline and diesel) and their byproducts, heavier fuels used by big ships like bunker fuel, or the spill of any oily waste or garbage.
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