Geometry

Question Analysis：
This question focuses on recognizing the shared part of two triangles.
The main focus is identifying common sides.

Key Concept Explanation：
△ABC and △DBC both contain points B and C
The side BC lies in both triangles
Other elements (AB, CD, A) are not shared

Step-by-Step Solution：
Identify triangle △ABC: contains points A, B, C
Identify triangle △DBC: contains points D, B, C
They overlap along line BC

Option Analysis：
A. Line segment AB ❌ — Only in △ABC
B. Line segment BC ✅ — Shared side
C. Point A ❌ — Only in ...