疲劳性骨膜炎损伤机制：肌肉牵扯学说
参考答案：
肌肉的反复收缩→骨膜受到牵扯、扭伤或张力增高→正常联系改变→骨膜松弛、淤血、水肿及骨膜下出血。
—Did you find the missing couple in the mountain yesterday?
—No, but we ______ to get in touch with them ever since.
A．had tried
B．have tried
C．have been trying
D．had been trying
知觉
