【Skill 3】Listen to and understand explanations about the maintenance of the internal environment of the body. 【Practice 1】What is the instructor saying? 1 When it is cold, the metabolism in the liver and muscles is promoted by the action of hormones such as thyroxine 2 When it is cold, metabolism in the liver and muscles is suppressed by the action of hormones such as thyroxine Proceed to Next Skill