I would say 4. To create a hypothesis, you would need some knowledge about what you're studying. This is where prior knowledge could come in handy.
Answer:
The sun
Explanation:
The is because the sun is the souce of energy
2. To focus a microscope using the high power lens you must first in low power center the specimen and make sure it is in focus. Then switch to high power and adjust using the fine adjustment or the smaller knob.
3. It prevents dust from settling on the scope and in the lenses.
Answer:
El sistema nervioso tiene dos partes principales: El sistema nervioso central está compuesto por el cerebro y la médula espinal. El sistema nervioso periférico está compuesto por todos los nervios que se ramifican desde la médula espinal y se extienden a todas las partes del cuerpo.