15. The first known bird fossils date to which era of time?
A. Permian
OB. Triassic
O C. Jurassic
O D. Cambrian

Which of the following is not a characteristic of carnosaurs? a. long narrow skulls b. strong forelimbs c. horn projecting from their skulls d. none of the above

Researchers randomly divide participants into groups. each group takes a different amount of omega-3 fatty acid supplements daily for a month. one group receives a placebo. the researchers measure the impact on cholesterol levels in the blood. what is the purpose of random assignment in this experiment? a, to produce treatment groups with similar characteristics b, to ensure that all people with high cholesterol have an equal chance of being selected for the study c, to increase the accuracy of the research results and prevent skewness in the data

What will happen if deforestation continue to destroy the green plant on the planet