In an experiment, tony placed a potted plant under a bell jar, completely sealing the jar to the table top. after placing a box over the bell jar for 24 hours, he measured the concentrations of oxygen and carbon dioxide in the gas in the jar. which statement best describes the measurements he would find in the jar, compared with the concentrations of oxygen and carbon dioxide in the classroom air?

a. oxygen concentration increased, carbon dioxide concentration decreased.
b. dioxide concentration increased; oxygen concentration decreased.
c. concentrations of both carbon dioxide and oxygen decreased.
d. concentrations of both carbon dioxide and oxygen increased.

Getting rid of my account might as well do it with some fun make sure to read all of this it is hilarious a plane was about to crash and there were 5 people on board and only 4 parachutes. the first person said: " i am roy keane, one of the best footballers in ireland. i am worth a lot of money and my fans need me so i think i should be saved." the others agreed and gave him one of the parachutes and off he went. the second person said: "i am gerry adams, a radical irish politician who can really my country and i think i should be saved." the others said: "o.k.", and gave him a parachute. the third person said: "i am george bush, president of the most powerful country in the world. everyone knows i am a really nice guy and everyone thinks i am stupid,but i'm not, so i am taking a parachute." and off he went. there were two people left, the pope and a 10 year old schoolgirl. the pope said: "child, i am old and frail and have lived my life while you are young, with everything before you. you take the parachute and i will stay with the aircraft and take my chance." "it's o.k." said the girl, "there are still two bush picked up my schoolbag."

One statements is an example of a scientific observation. another statement is an example of a scientific explanation. identify the correct statement for each category to illustrate how scientific explanations are inferred from scientific observations.

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