健康人的尿液不含葡萄糖是因为（ ）
A．尿液流经肾小球时被重吸收
B．尿液流经肾小管时被重吸收
C．原尿流经肾小球时被重吸收
D．原尿流经肾小管时被重吸收
血液流经肾小球时，血液中的尿酸、尿素、水、无机盐和葡萄糖等物质通过肾小球的过滤作用，过滤到肾小囊中，形成原尿．当原尿流经肾小管时，原尿中对人体有用的全部葡萄糖、大部分水和部分无机盐，被肾小管重新吸收，回到肾小管周围毛细血管的血液里．原尿经过肾小管的重吸收作用，剩下的水和无机盐、尿素和尿酸等就形成了尿液．所以健康人的尿液不含葡萄糖是因为原尿流经肾小管时被重吸收．
故选D
| 下列每句的画线部分中有一处错误，找出并改正 。 | |
| ( )1. For many teenagers, Du Fei has a few habits that are not so good for him. A B C ( )2. I would rather go out than to stay at home. A B C ( )3. Exercising helps teenagers to stay health. A B C ( )4. He finded it important to learn English well. A B C ( )5. His teachers want him change his attitude. A B C | _________ _________ _________ _________ _________ |
