In the thymus, thymic stromal cells(TSCs) are interconnected into a network structure. These cells carry a large number of surface molecules and can secrete a variety of thymic hormones and cytokines, which provides a suitable microenvironment for the development and maturation of thymocytes. The types of TSCs include ( ). A: epithelial cell B: macrophage C: dendritic cell D: neutrophil

Which of the following is NOT true of interleukins? () A: They<br/>are cytokines which can be produced by various cells of the immune<br/>system. B: They<br/>are hormones which allow one cell to communicate with another cell. C: They<br/>are in need of receptors on the target cell in order to mediate their<br/>effects. D: They<br/>are able bind antigen with a high level of specificity. E: They<br/>are able to modulate various aspects of the B-cell arm of immune<br/>system.

力量训练就是将所锻炼部位的肌肉纤维产生细微的破坏，受伤的肌肉组织会释放一种名为Cytokines（细胞活素类）的物质，身体收到信号后就会修复细微损伤的部位。但是修复的过程中会产生“”，就和手上的老茧一样，越来越厚。肌肉变大后力量会增加，如果不能持续给肌肉刺激，就会出现萎缩，但是萎缩之后的肌肉重新练起来也相对容易。