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cycle to control the radial power distribution in the core, or they may reside out of the core and only inserted and withdrawn to make quick small changes to the power level.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.
Understanding Rhetoric. Writing instructors and many other professionals who study language use the phrase ârhetorical situation.â This term refers to any set of circumstances that involves at least one person using some sort of communication to modify the perspective of at least one other person.