A scientist noticed that in acidic pond water some salamanders developed with curved spines. This was an example of a(n) А
research
o
B
inference.
о
С
observation
D
hypothesis

С  observation

Explanation:

This mode of investigation is an example of observation.

Observations are carried out using our senses and keen inquisitiveness. It can take place within a short period of time or an extended duration.

So; noticing the change in shape of the salamanders is making an observation.

Our sight, smell, taste e.tc are all observational tools.

answer: after carbon dioxide enters the leaf through stomata it moves into the mesophyll cells where photosynthesis occurs and glucose is constructed. respiration occurs when glucose (sugar produced during photosynthesis) combines with oxygen to produce useable cellular energy.

explanation: