What is a lightyear? A: It is the distance that light can travel in one year.
B: The distance between the Earth and the Sun
C: Distance between the Earth and the Moon
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

Sperm pass through the and connect to a short ejaculatory duct. vas deferens prostrates seminiferous tubules none of the above

How can antibodies "remember" a particular bacterial invader or "antigen" on that invader?