Answer:
These atoms will decay as the rock ages, and by measuring the ratio of radioactive isotopes within the rock, scientists can figure out how long it has been around. In 1913, geologist Arthur Holmes published “the Age of the Earth,” the first major effort to date the planet using radiometric dating.
Answer:
An example of a president's involvement in civic life is throwing the first pitch at a baseball game.
Explanation:
First of all, let's see all the answers a) is wrong because it is a message the president has to give to the congress of the United States and it is a task considered in his duties as president.
Second, b) is correct because throwing the first pitch at a baseball game is not an activity considered into his presidential duties or responsibilities.
Third, c) is incorrect because even though it doesn't have the presidential duties involved in it. It does require him or her to adopt a formal posture in the camera and be prepared for the topics because as a president he or she has to preserve his or her presidential image. The president is not allowed to behave inappropriately. It is a leadership role and it is required to behave with high moral standards.
Fourth, d) appointing an ambassador is incorrect because it forms part of his presidential duties and responsibilities.
