本学期,你已经学过“人体的呼吸”等方面的知识。你知道人体需要的氧气是怎样进入身体的吗?你可能会说是通过肺进入的,实际上,你只说对了一半。肺是肌体与外界进行气体交换的场所,进入肺内的氧气还要与血液进行气体交换,然后通过血液循环,才能被身体内的细胞利用。当然,肺的气体交换量在一定程度上也影响了与血液的气体交换量。 This semester, you have learned about the “breathing of the human body.” Do you know how the oxygen needed by the human body enters the body? You may say that you entered through the lungs. In fact, you only said half right. The lungs are the place where the body exchanges gas with the outside world. The oxygen that enters the lungs needs to exchange gas with the blood, and then it can be used by cells in the body through blood circulation. Of course, the amount of gas exchanged in the lungs also affects the amount of gas exchange with blood to a certain extent.