Explanation:

- Section 115: Talks about the doctrine of estoppel, which is related to preventing a person from denying facts they previously declared as true. It isn't related to cross-examination.

- Section 125: Discusses the privilege regarding official communications. It's about protecting the disclosure of confidential information, unrelated to the witness cross-examination process.

- Section 135: Outlines the order of production and examination of witnesses, providing a general guideline on how examinations should be conducted, but not specifically about cross-examination.

- Section 145: Specifies how witnesses can be questioned about previous statements they made in writing, which directly relates to cross-examination procedures.