Which natural events likely caused Earth's past mass extinctions?

Select all the true statements about the cosmic microwave background radiation

Which set of characteristics best describes sedimentary rock? a) largest type of rock, made of organic matter, hardest type of rock b) often contains layers, forms near sources of water, contains fossils c) least abundant type of rock, made of other rocks, made mostly of minerals d) most abundant type in earth's crust, made of magma/lava, contains no fossils

Which statement best describes a typical difference that could be found between the "analysis" and "conclusion" sections of a lab report? a) only the "conclusion" describes errors that occurred during the experiment, and only the "analysis" section suggests further research. b) only the "analysis" section includes specific data comparisons, and only the "conclusion" section suggests further research. c) only the "analysis" section discusses whether the original hypothesis was supported, and both sections include graphs of data. d) only the "conclusion section discusses whether the original hypothesis was supported, and both sections suggest further research.(the answer is b i just took the test)