What is the best description of organisms of the precambrian era?

Astudy was performed on 20 trees to test the effectiveness of a new fertilizer. the results of this specific study is brought into question. what would possibly improve the reliability of the results?

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."

Which of these serves as a reference for comparison during a scientific investigation? a)outcome variable (dependent variable) b) test variable (independent variable) c)control group d)hypothesis