以下关于颌下腺涎石多见的原因，错误的是（）
A.颌下腺导管弯曲而长，涎液流动缓慢
B.导管口大，位于口底
C.颌下腺分泌的涎液含黏液量较腮腺为低
D.颌下腺涎液浓而黏稠
E.颌下腺涎液较腮腺涎液更偏碱性
参考答案：C
解析：考点：颌下腺涎石的病因。涎石病是在腺体或导管内发生钙化性团块儿引起的一系列病变。多见于下颌下腺。下颌下腺为混合性腺体，分泌的涎液富含黏蛋白，较腮腺分泌液黏滞，钙的含量也高出2倍，钙盐容易沉积，故D、E正确，而C不对。下颌下腺导管自下而上走行，腺体分泌液逆重力方向流动。导管场，全程曲折，这些解剖结构使涎液易于淤滞，故A，B正确。本题选C。
| 阅读理解。 |
| Last September I decided to fly from my hometown, Phoenix, to visit my sister in Seattle. I wanted to take my dog Rosie with me, so I spoke to my vet (兽医) before I booked the tickets. Rosie would have to travel in a large wooden box, and I wanted to check that she would be OK. The vet said that Rosie would be fine because it was only a short flight. When the plane landed in Seattle at five o'clock, I asked the flight attendant if I could stay in my seat until Rosie was taken off the plane. The flight attendant told me to get off the plane immediately, and that I should wait for Rosie at the baggage claim area (行李认领处). So I went to the baggage claim area and waited until all the baggage had been taken off the plane. Soon I was the only person waiting and there was still no sign of Rosie. After forty-five minutes, I asked a woman who worked for the airline if she could find out where my dog was. After I'd waited another thirty minutes, she told me that the plane was now flying to Los Angeles. Rosie was still on the plane! It wasn't until eleven thirty that night that the airline found Rosie in Los Angeles. There were no more flights that night so she had to spend the night in her box at Los Angeles airport. I got Rosie back the next morning, but by this time she had been in her box for over eighteen hours. Poor Rosie! |
| 1. Ruth flied to Seattle to _______. |
[ ] |
| A. pick up her dog B. visit her sister C. travel around D. book the tickets |
| 2. Rosie spent the night _______. |
[ ] |
| A. in Phoenix B. on the plane C. in Ruth's house D. at Los Angeles airport |
| 3. The vet told Ruth that _______. |
[ ] |
| A. she could take Rosie with her on the plane B. her sister should prepare a big wooden box C. Rosie should spend a night in the box D. she could be in her seat to wait for Rosie |
| 4. Ruth waited at the baggage claim area for _______. |
[ ] |
| A. forty-five minutes B. thirty minutes C. more than an hour D. eighteen hours |
| 5. From the passage we can know that _______. |
[ ] |
| A. the box with Rosie in was taken away by others B. Rosie wasn't taken off the plane in Seattle C. it was not allowed to take pets on the plane D. the attendant was not very polite |