Which of the following is an accurate way to explain why light from distant galaxies experiences red shift?

What is the reason for the “scramble for africa”?

Read the article about the fraser river, one of the most important rivers in canada. what is the most important species of fish in this river? why are the numbers of these fish declining?

Some gamma ray bursts are hypothesized to come from mergers of neutron stars or black holes. if this hypothesis is correct, what else should we in principle be able to detect from such mergers? a. gravitiational waves b. x-ray bursts c. significant disruption of gas thousands of light-years away in the surrounding galaxy d. an "afterglow" of bright visible light, lasting for weeks