单选题结构各杠杆相同，其弯矩图形状所对应的受力结构是（　　）。<br/> <img border="0" alt="" src="https://tuku.weimei168.com/uploads/upimg/20251122/18930555_0.jpg"><br/> <img border="0" alt="" src="https://tuku.weimei168.com/uploads/upimg/20251122/18930555_0_1.jpg">