下列关于二尖瓣关闭不全患者早期病理生理改变的叙述，正确的是
A．左心房压力负荷增加
B．左心室压力负荷增加
C．左心室容量负荷增加
D．肺静脉压力负荷增加
E．肺静脉容量负荷增加
参考答案：C
解析：二尖瓣关闭不全患者，收缩期左心室射出的血液经关闭不全的二尖瓣口反流回左心房，与肺静脉回流至左心房的血液汇总，在舒张期充盈左心室，使左心房和左心室容量负荷骤增(C)，左心室舒张末期压急剧上升。左心房压也急剧升高，导致肺淤血，甚至肺水肿，之后可致肺动脉高压和右心衰。
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| One day at the end of the class, a wise teacher told each of her students to 1 a plastic bag and a bag of potatoes to school. The next day she told her students: "From today on, for every person you don't like in your lives, you can choose a potato, write the person's name and the date 2 it and then put it in the plastic bag." Day after day, some of the students' bags were very 3 . They were then told to carry this bag with them everywhere they went for a week. They would put it inside their quilts 4 , on the seats when sitting in a car or on a bus , and next to their desks at school. The days carrying the bag around with them 5 students get to know what a weight they were carrying in their minds. They had to pay attention to it all the time 6 they wouldn't forget it. As time passed by, the potatoes went bad and 7 nasty(恶心). They all tried to get rid of them. Too often we think of tolerance(宽容) as a gift to 8 people, and it clearly is for ourselves! If we choose to keep our sadness and hatred(仇恨)in our 9 , we will have to carry them around all our lives. Do you think you have got 10 from the wise teacher and what she asked her students to do? | |||
| ( )1. A. take ( )2. A. in ( )3. A. heavy ( )4. A. in the morning ( )5. A. kept ( )6. A. as soon as ( )7. A. sounded ( )8. A. another ( )9. A. hands ( )10.A. anything | B. bring B. at B. strong B. in the afternoon B. made B. since B. tasted B. other B. eyes B. nothing | C. put C. on C. light C. during the day C. asked C. so that C. smelt C. the other C. stomachs C. somebody | D. show D. with D. big D. at night D. allowed D. until D. felt D. others D. hearts D. Anybody |
