Which of the following is true?
A
The sun has very little effect on natural cycles.
B
The sun is only helpful and is never dangerous.
The sun is very important, but its rays can also be harmful.
D
The sun is very dangerous and doesn't really support life on Earth.

Why is it important for scientists to review and repeat the work of other scientists? 1.a scientific theory must be tested three times before it is proven. 2.the scientific method only applies to repeated experiments. 3.an experiment may have had errors that the scientists didn't recognize. 4.the results of individual scientists may be influenced by bias. 5.an experiment must be performed twice before the data can be analyzed.