（）的变动引起均衡价格与均衡数量同方向变动。
参考答案：需求
In terms of contract law, explain the internal requisite of subject matter which is essential for the validity of a contract. (10 marks)
屈髋关节的肌有（）
A．髂腰肌
B．缝匠肌
C．股二头肌
D．股直肌
