Grey rods can be inserted in the core for most of the cycle to control the radial power distribution in the core, or they may reside out of the core and only inserted and withdrawn to make quick small changes to the power level. The Russians have used Dy in the form of Dysprosium titanate as a control rod material.
A rhetorical question is a device used to persuade or subtly influence the audience. It's a question asked not for the answer, but for the effect. Oftentimes, a rhetorical question is used to emphasize a point or just to get the audience thinking. Sometimes, a rhetorical question is asked with the asker already knowing the answer, such as the weather example.
Something that strikes me is that there are many definitions on what rhetoric is. Rhetoric is using selective words to create an argument that persuades the reader of something. It the manipulation of words to produce a certain thought or reaction from readers.fter reading this article, I have a better understanding on the definition of rhetoric. Now I see rhetoric as a way of communication to persuade and inform a target audience. Rhetoric is also a study of communication for others.