Wouldn't the first question be an argument?

Premise -> Cross sections of pigs' teeth found in an excavated Stone Age trash pit revealed bands of remarkably constant width except that the band deposited last, which was invariably translucent, was only about half the normal width.

Conclusion -> The teeth of some mammals show “growth rings” that result from the constant depositing of layers of cementum as opaque bands in summer and translucent bands in winter.

The argument requires some assumptions being that "The bands of constant width found on the pigs result from constant depositing of layers" However, since pigs are mammals, the truth of the premise does make the conclusion more likely

#feedback The player on these videos do not work all of the time, not allowing me to change viewing speed or change subtitles settings. In this video, subtitles covered the passage and I could not read all of it without reloading the page.

Makes sense!