Answer: It is true about the type of reaction that it is a single replacement reaction, and the cations in the two ionic compounds are different.
Explanation:
When one element in a compound is replaced by another element in a chemical reaction then it is called a single replacement reaction.
For example, 
Here, potassium metal is replacing the sodium metal in the sodium chloride compound.
As metals become cation by losing an electron in a chemical reaction.
Thus, we can conclude that it is true about the type of reaction that it is a single replacement reaction, and the cations in the two ionic compounds are different.
Answer:
A. modern organisms closely resembling fossils
Explanation:
Fossils are defined as the preserved remains or traces of living organisms from past.
Fossils are considered as an evidence for evolution because they represent the existence of life on earth and shows the difference between the life in past that life on earth today. With the help of fossil, it is easy to determine the age of fossils which further help to determine that how modern organisms have evolved from the past.
Hence, the correct answer is "A. modern organisms closely resembling fossils".
<span>Acid rain is precipitation that contains high levels of nitric or sulfuric acid. Natural and industrial sources can release sulfur dioxide and nitrogen oxide into the atmosphere, leading them to combine chemically with oxygen and water to form their respective acidic molecules. These acids are then deposited through rain or dust depending on the climate of the region. While acid rain can occur anywhere in the world, it is prevalent in regions that have high industrial activity.</span>
Eyepiece, finder-scope, optical tube, aperture, focuser, and mount
