A scientist begins working by trying to explain a natural occurence that is... 1. consistent
2. observable
3. In a lab
4. undetectable​

Observable

Explanation:

An observable phenomenon leads to an hypothesis.

2. observable

Explanation:

The scientific method relies on a scientist being able to study an occurrence and understand it. So, all the occurrences must be observable; otherwise, they cannot be studied. If the patterns are observable then one can follow the scientific method and experiment with the different variables. All science depends on the observable world and the people that study it.

sex cells are usually half's then they find another half and make a fertilize egg

a=c and then d= c because of the band so you get ac/dc and you add them together you get sound waves