The correct answer to this open question is the following.
Mr. Kiesler has these students hooked! A sign of an engaging lesson is when students are eagerly asking questions for the sake of gaining knowledge. Consider the different techniques he has used.
Mr. Kiesler makes his students pay attention by asking quick questions to confirm they are paying attention. This action helps Mr. Kiesler to confirm that the students are indeed paying attention which they are because they know that at any moment, the teacher can choose one of them to ask a question.
Mr. Kiesler also asks their students to reflect questions in pairs, to encourage active participation. He also makes his students write down important notes in their notebooks to help memorize concepts. When he is watching some video, he continually makes pauses to ask questions and opinions, so he can confirm that students are learning.
These techniques are so important to make sure students are paying attention, they are no distracting, and this increases the chance to better learn the lessons.