7. An investigator is drafting an outline for questioning a witness who is defending a public crime. He intends to ask only such questions that can be answered with a "yes" or "no" (of course, whether to ask a certain question depends on the witness's answer to the previous question). The investigator believes that all answers will be truthful, and he estimates that, under any questioning outcome, the number of questions asked will not exceed 91.

Try to explain: The investigator can draft a questioning outline that does not exceed 105 questions, to cope with the possibility that the defense witness might give an untruthful answer to any one question (of course, it is also possible that all answers are truthful).

Note: If you can only draft an outline with more than 105 questions, then please provide the best solution you can come up with.
7. Denote the best outline as $S$. First, ask 13 questions according to outline $S$, then
Figure 6

ask a verification question: "Do you agree with the previous set of questions?" If the answer is "No," it indicates that there is no untruth, so continue asking questions according to outline $S$, still in groups, with the number of questions in each group being 12, 11, ..., 4, 3, 2, 1, and ask the verification question after each group. If the witness is honest, a total of $91+13=104$ questions will be asked. If the witness answers "Yes" to the verification question, then the questions in that group will be repeated... If dishonesty is reflected in the $i$-th group of questions, then $i$ verification questions have already been asked, and $14-i$ questions will be repeated, thus adding a total of 14 questions.