Answer:
b. measuring the pulsations of the Sun from stations around the world.
Explanation:
The Global Oscillation Network Group (GONG) is a community-based program that wants to conduct a detailed study of the internal structure of the sun by using helioseismology. GONG relies on a team of six observatories around the world to perform its work. One of the duties of GONG is to measure the pulsations of the Sun from six stations located all over the world.
B. Guatemala is considered part of middle America. It is located between North America and South America, under Mexico
Biotic factors are organisms that interact with non-living & living parts of an ecosystem.
Egs. badgers, worms, fungi, bacteria, insects.
Answer:
were introduced into American geography in the 1920s by Carl Sauer
