Section 356 Of Article 1. General Provisions From California Evidence Code >> Division 3. >> Chapter 4. >> Article 1.

. Where part of an act, declaration, conversation, or writing is given in evidence by one party, the whole on the same subject may be inquired into by an adverse party; when a letter is read, the answer may be given; and when a detached act, declaration, conversation, or writing is given in evidence, any other act, declaration, conversation, or writing which is necessary to make it understood may also be given in evidence.