The lecture revises the idea presented in the text, that Rembrandt was not the artist who painted the famous painting "Portrait of an Elderly Woman in a White Bonnet”.
The inconsistency between the white cap, which identifies the woman as a servant, and the expensive fur collar she wears dissolves as the Professor explains that the fur collar was apparently painted over the original painting to increase its worth by displaying an aristocratic woman.
In addition, the assumption that light and shadow in the painting do not fit together is refuted by the fact that in the original painting, the woman wears a light cloth that illuminated her face. Thus the presentation of light and shadow was indeed very realistic and accurate, as it is characteristic of Rembrandt’s paintings.
Finally, the mystery of the panel consisting of patches glued together is also solved in the lecture. Actually, the wood panel was later enlarged to make it more grand and valuable, but the original painting was painted on a single panel, as Rembrandt would have done it. Furthermore, the wood is of the same tree used in other Rembrandt paintings, like the "Self-Portrait with a Hat”.
All the information point out that Rembrandt is the painter of the controversial painting.
氟自来水(adding fluoride in public water)
3.对骨骼有好处(decrease bone diseases)
The speaker refutes the reading's argument about the benefits of adding fluoride to pipe water by providing contradictory evidence about
pipe water's fluoride's effectiveness in preventing cavities in teeth, killing bacteria, and decreasing bone diseases.
Firstly, the speaker points out that the short contact of fluoride with teeth will not enable the fluoride to prevent cavities, as the reading argues. Instead, the water will pass the mouth and teeth quickly and go directly to the stomach.
Another argument raised in the lecture is that fluoride could undergo chemical reactions with heavy metals in the pipe, such as lead. This will create toxic substances which will pose serious health threat. In this way fluoride could be even more deadly than bacteria. Although the fluoride, as the reading says, will kill some bacteria, the cure here is worse than the disease.
In the end, the speaker maintains that overdose of fluoride will backfire to human bones. Although the reading illustrates that fluoride will improve bone strength, the lecture says overdose will cause serious damage to human bones.