It's not a case of whether Enid wants to give evidence or not. If she overheard a criminal conversation, it's her bounden duty to report it to the police. 现在的问题不是伊妮德是否愿意作证。假如她偶然听到罪犯的谈话，那么，向警方报告是她义不容辞的责任。
It is required (of me) that I give evidence. 要求我提供证据。
You may be called to give evidence at the trial. 法庭可能传你去作证。
