专升本备考，这些坏习惯你千万不能有！

We all love a hero,and rescue dogs are some of the biggest heroes of all．You will often find?them going above and beyond duty to save someone,risking—and at times losing—their lives in the?process．
Rescue dogs are generally found in the Sporting and Hunting Groups,or from the traditional?Herding Group．These types include the Bloodhound,Labrador Retriever,Newfoundland,German?Shepherd,Golden Retriever,and Belgian Malinois—all of which are chosen for search-and-rescue?duty because of their amazing physical strength,loyalty,and their tendency for mental stability．
These types also have a keen sense of hearing and smell—to better locate lost individuals—and?are often able to access hard-to-reach areas．As highly trained animals,they serve in many different?fields,including specialist search,snow slide rescue,dead body location,and tracking．
To overcome obstacles and succeed when performing the demanding duties of a search-and-rescue?worker,a dog must display certain qualities．In addition to intelligence and strength,the dog must be?swift,confident,easily trainable,adaptable,and have a high level of stamina(耐力)and endurance．A strong sense of group cooperation and an ability to engage in friendly play during“down”time is also required of search-and-rescue dogs．
A rescue dog goes through many,many hours of intensive training to be fit for duty．Training is not for the faint-hearted．Certification training can take from two to three years,working three to four hours a day,three to six days a week,often in group,team-oriented sessions．
Each search-and-rescue field requires different types of training．Rescue training,for instance,includes“air scenting”—where dogs are trained to smell the air for the victim′s scent(气味)and then follow the scent to the person．This ability is crucial to finding victims trapped under collapsed buildings and snow slide．

What is the passage mainly about?

A.Selection process of rescue dogs．
B.Qualities and training of rescue dogs．
C.Risks rescue dogs are faced with．
D.Types of tasks rescue dogs can perform．

呼吸商是( )

A.在一定时间内机体摄入的氧与呼出的二氧化碳量的比值

B.一定时间内机体呼出的二氧化碳与氧摄入量的比值

C.呼出气与吸入气的比值

D.呼出气与肺容量的比值

E.二氧化碳产生量与吸入气的比值

在不同政治经济制度下，学制在很多方面存在共同特点，如入学年龄，大、中、小学阶段的划分，在很多国家都是一致的。这是因为，学制的建立要受（ ）。

A.政治经济制度的影响
B.生产力发展水平与科学技术发展状况的影响
C.青少年身心发展规律的影响
D.本国学制的历史和国外学制的影响