手机群呼群聊业务是指一个人拨打电话，一次呼叫多人，同时与多人聊天的业务。本业务支持（

腰椎间盘突出症左侧直腿抬高试验右侧发生疼痛，右侧腰部有压痛，并放射到右下肢，其突出髓核位置可能是（）

A.右侧神经根的内侧

B.右侧神经根的外侧

C.中央型髓核突出

D.左侧神经根的内侧

E.左侧神经根的外侧

分母相同的分数相加减，______不变，______相加减．分母不同的分数相加减，先______，再______．

关于同步卫星(它相对于地面静止不动)，下列说法中正确的是[ ]

A.它一定在赤道上空

B.同步卫星的高度和速率是确定的值

C.它运行的线速度一定大于第一宇宙速度

D.它运行的线速度一定介于第一宇宙速度和第二宇宙速度之间

阅读理解。

     Science can't explain the power of pets, but many studies have shown that the company of pets can help

lower blood pressure (血压) and raise chances of recovering from a heart attack, reduce loneliness and spread

all-round good cheer.

     Any owner will tell you how much joy a pet brings. For some, an animal provides more comfort than a

husband/wife. A 2002 study by Karen Allen of the State University of New York measured stress (紧张)

levels and blood pressure in people - half of them pet owners-while they performed 5 minutes of mental

arithmetic (算术) or held a hand in ice water. Subjects completed the tasks alone, with a husband/wife, a

close friend or with a pet. People with pets did it best. Those tested with their animal friends had smaller

change in blood pressure and returned most quickly to-baseline heart rates. With pets in the room, people

also made fewer math mistakes than when doing in front of other companions. It seems people feel more

relaxed (放松) around pets, says Allen, who thinks it may be because pets don't judge.

      A study reported last fall suggests that having a pet dog not only raises your spirits but may also have

an effect on your eating habits. Researchers a Northwestern Memorial Hospital spent a year studying 36

fat people and their equally fat dogs on diet-and-exercise programs a separate group of 56 people without

pets were put on a diet program. On average, people lost about 11 pounds, or 5% of their body weight.

Their dogs did even better, losing an average or 12 pounds, more than 15% of their body weight. Dog

owners didn't lose any more weight than those without dogs but, say researchers, got more exercise

overall - mostly with their dogs-and found it worth doing.

1. What does the text mainly discuss?

A. What pets bring to their owners.

B. How pets help people calm down.

C. People's opinions of keeping pets.

D. Pet's value in medical research.

2. We learn from the text that a person with heart disease has a better chance of getting well if _____.

A. he has a pet companion

B. he has less stress of work

C. he often does mental arithmetic

D. he is taken care of by his family

3. According to Allen, why did the people do better with pets around when facing stressful tasks?

A. They have lower blood pressure.

B. They become more patient.

C. They are less nervous.

D. They are in higher spirits.

4. The research mentioned in the last paragraph reports that _____.

A. people with dogs did more exercise

B. dog lost the same weight as people did

C. dogs liked exercise much more than people did

D. people without dogs found the program unhelpful

根据《SDH长途光缆传输系统工程验收规范》（YD/T5044—2005），关于铁架安装，下列说法不正确的是（）

A.铁架安装位置应符合施工图的平面设计，偏差不得超过50MM

B.列铁架应成一直线，偏差不应大于50MM

C.列铁架两侧的侧板宜分别与机架顶部前后面板相吻合

D.主铁架的盖板、侧板、底板安装应完整