已知，如图，AB与CD相交于点O，∠1=∠C，∠2=∠D.求证：AC∥DB.---Based on the image provided, there is no question stem, options, or other relevant text present. The image contains a geometric diagram. **Diagram Description:** * **Type:** Geometric figure. * **Main Elements:** * **Points:** Five labeled points: A, B, C, D, and O. * **Lines/Segments:** * Two intersecting straight lines forming line segments AB and CD. * The intersection point of lines AB and CD is labeled O. * Line segments AC and BD connect the endpoints of these segments, forming two triangles. * **Shapes:** Two triangles are formed: triangle AOC and triangle BOD. * **Angles:** Two angles are labeled: * Angle 1 is formed at point O, between lines OC and OA (angle AOC or angle COA). * Angle 2 is formed at point O, between lines OB and OD (angle BOD or angle DOB). * **Relative Position and Direction:** * Point O is the intersection of line segment AB and line segment CD. * Points A and B are on the line passing through O. Points C and D are on the other line passing through O. * Points A and B are on opposite sides of O. * Points C and D are on opposite sides of O. * Angle 1 and Angle 2 are vertically opposite angles at the intersection point O. * Triangle AOC has vertices A, O, C. * Triangle BOD has vertices B, O, D. * **Labels and Annotations:** The points are labeled A, B, C, D, O. Two angles at O are labeled 1 and 2. No question text, options, or other related information is present in the image.