健康成人每天形成的原尿150升左右，而每天的尿量却仅为1.5升左右，原因是（ ）
A．肾小球的过滤作用
B．肾小管的重吸收作用
C．膀胱的贮尿作用
D．汗腺排出汗液
从题干中可以看出，原尿是150升，而形成尿的量却是1.5左右，这应该与原尿到形成尿液的过程有关系．
A、血液经肾小球的滤过作用后形成的是原尿，并没有形成尿液，与尿量大小没有直接关系．此选项不符合题意．
B、原尿经过肾小管的重吸收作用，其中的大部分水、部分无机盐和全部的葡萄糖被重新吸收回血液，剩下的其他物质如尿素、一部分无机盐和水等由肾小管流出，形成尿液．因此人虽然每天形成原尿的原尿不少，但由于肾小管的重吸收作用，大部分物质又重新吸收回血液，形成的尿量就大大减少．此选项符合题意．
C、尿形成以后，只是暂时储存在膀胱中，到定量后就就产生尿意排出体外．此选项不符合题意．
D、汗腺排出汗液，虽然也是排出废物，但与尿的形成和排出没有关系．此选项不符合题意．
故选：B．
Mr.Smith works in an office. He’s very busy 小题1:.Every evening, when he comes back from his office, he’s always tired and wants to go to bed early. 小题2: .She doesn’t stop talking until she falls asleep, but it’s usually too late and Mr. Smith has to get up on time in the morning when she is asleep. One day the man felt terrible and couldn’t go to work. 小题3: ,and Mrs. Smith went to the hospital with him. The woman told the doctor all at once and the doctor understood why. He wrote out a note(处方). 小题4:, the doctor said to her,“The bottle of medicine is for your husband and the pills are for you.” “For me?”the woman said in surprise(惊讶地),“I’m fine. I don’t need any medicine!” “I don’t think so,madam,”said the doctor,“小题5: .Your husband will soon be all right if you take them.”.
从方框中所给的选项中选出能填入空白处的最佳选项，补全短文，其中有一项为多余选项（10分） |