Answer: C) a factor that may affect an experiment or investigation
Explanation:
This is the best answer. A and B can be eliminated. D describes a controlled variable which is more specific than a scientific variable, thus C is the best answer. It is the best description of just a scientific variable.
Answer:
most likely Asthma
reasons:
decreased oxygen intake by breath (possible obstruction) and increase intake by cells due to high demand
For Absolute dating they assign a numerical date to each rock layer studied
For relative dating they go Through geological dating and stratigraphy processes. Also, they use Uranium Dating.
Answer: corals, crabs, oysters and urchins
Explanation: