Dear teachers and schoolmates,
May I have your attention, please? I have① a announcement to make. In order to help us learn more about the Internet, the Students’ Union is going to hold a lecture. Professor Zhang from the Computer Department at Nanjing University will give us a talk. The lecture will② hold on Wednesday, the tenth of October. It will begin at 4:30 pm in Room 302 of the library building.
That’s all. Thank you!
② hold改为be held。此处lecture和hold为被动关系，应用被动语态。