问题 单项选择题 A1型题

关于妊娠母体变化的描述,哪项正确()

A.妊娠初期动脉血压增加,脉压减小

B.妊娠后肺功能降低,故合并呼吸系统疾病时,病情易加重

C.孕妇心搏量随妊娠的进展而不断增加,到孕末期达峰值

D.因受孕激素影响,输尿管增粗、蠕动减弱、尿流缓慢,加上子宫压迫,易发生肾盂肾炎

E.垂体前叶增大,故促性腺激素分泌增多

答案

参考答案:D

解析:妊娠早、中期动脉血压偏低,在妊娠晚期血压轻度升高。一般收缩压无变化,舒张压因外周血管扩张、血液稀释及胎盘形成动、静脉短路而轻度降低,使脉压稍增大。妊娠后肺通气量、潮气量、肺泡换气量均增加,肺功能并无降低。心搏量自妊娠第10周开始逐渐增加,至妊娠32周达高峰,维持此水平直至分娩。妊娠期腺垂体增生肥大明显,在妊娠早期,继妊娠黄体后由胎盘分泌大量雌、孕激素,对下丘脑及腺垂体起负反馈作用,使FSH及LH分泌减少。

阅读理解

阅读理解。

    Hiking is very good for exercise and fun. Many hikers like to hike in countryside, in forest, and in mountains. Just walking for fun is the first kind of hiking. A lot of people like to hike in city parks or just on the sidewalks. 

    A hike can take a few hours or weeks. For most hiking, people just need clothing and shoes that are good for the weather. Beginning hikers should start with walks that they can do in one day. As you get stronger, you can go in overnight hikers. Later you can go on longer that can last for days or weeks.

    For safety(安全) , children should hike with someone. You should always have one or two friends with you. It is also a good idea to carry a map with you.

    Backpacking is one kind of hiking. People carry food, clothing and other things on their backs in a pack. Backpackers can stay many days in places where there is no food to buy. They carry what they need on their backs.

    It seems that backpacking is now popular in the world. Just put on your hiking shoes and take a hike!

1. The first and the easiest kind of hiking is ______.

A. overnight hikes                  

B. walking

C. backpacking                    

D. running and flying

2. Beginning hikers should start with walks just because ______.

A. it can finish in one day

B. hikers are very busy

C. the weather is not so good

D. clothing and shoes are too heavy 

3. Hikers should go on hiking with others because ______.

A. they can talk with each other

B. they can keep safe

C. lots of people do so

D. they have no maps with them 

4. To carry______with you is a very good idea when you go on hiking.

A. a book                        

B. a map

C. a bag                        

D. an umbrella

5. To carry what you need on your backs when you go on hiking is called ________. 

A. single hiking                  

B. double hiking

C. backpacking                  

D. backing 

单项选择题