Answer:
Angle of light source
Explanation:
Independent variable is the variable that the experimenter changes or manipulates in an experiment in order to bring about a measurable response, which is the dependent variable.
In this question, a student wants to investigate the effects of phototropism in bean plants. She places a light source directly above one plant, at a forty-five degree angle to another, and at a ninety-degree angle from the third. This shows that the variable being manipulated (independent variable) is the ANGLE OF THE LIGHT SOURCE.
Well it depends what are the actions listed below
You forgot to include the following choices but no worries I did this question before and the answers are:
advances in technology
increases understanding on environment
etc
The four laws or principles that are involved with the study of Stratigraphy are the following:
1. Principle of original horizontality
2. Law of superposition
3. Law of crosscutting relationships
4. Principle of Lateral Continuity
5. Principle of Faunal Succession
6. The Law of inclusions
Therefore, the correct answers would be 1, 2 and 4. Hope this answer helps.
