Plants typically absorb carbon dioxide and give off oxygen during the day. However at night this tends to be the opposite and plants will absorb oxygen and give off carbon dioxide. Please expalin:
A) What are the names of 2 processes are happening in plants that cause this
B) when each process happens
C) why each process happens when it does
(this is science)

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

The bacteria found in soil is usually harmful and measures are taken to remove any traces of microorganisms. true or false

Speed is the ratio of the distance of an object moves to