The answer is: A. collecting data
During this process , researchers would use their observational skills and record every notable occurrence that happen to the variables.
The focus on this process is simply to add all relevant data without making any analyzation. That process come later on after the researchers started to change the variables in order to see whether it would create a correlation.
The greenhouse effect.
Hope this helps!
-Payshence xoxo
Most reasonable answer is the swallowable camera one. mris and cat scans were invented in the 70s and the rest of the answers are around the 1800s or before.
A good extraction solvent should have a strong solubilizing capability for the compound of interest, it should be immiscible or only weakly misciblewith the matrix solvent ( the first solution or mixture containing the compound from its natural source, e.g., water/ether. water/ chloroform, etc. If possible the extraction solvent should be non-flammable, non-toxic or of low toxicity, reasonably volatile, and of low eco-impact. Inexpensive and available, of high purity , and shelf stable. If one is determining the compound of interest by UV/Vis spectrophotometry or fluorescence, the solvent should have extremely low absobance or emission at the wavelength of analysis
• high solubility for the solute and low solubility for the carrier liquid.
• density difference vs. the carrier liquid greater than 150 kg/m. ...
• mid-level interfacial tension (5–30 dyne/cm)
• high resistance to thermal degradation.
