我想报考明年的普通专升本，请问普通专升本第一学...

不属于椎一基底动脉分支的是 （　　）

A.小脑上动脉

B.小脑下前动脉

C.脊髓前、后动脉

D.迷路动脉

E.脉络丛前动脉

关于排尿反射的叙述，哪一项不正确（　　）

A.感受器位于膀胱壁上

B.初级中枢位于骶段脊髓

C.反射过程存在负反馈控制

D.排尿反射受意识控制

E.反射过程存在正反馈控制

Can animals be made to work for us?Some scientists think that one day animals may be trained to do a number of simple jobs that are now done by human beings.
They point out that at a circus,for example,we may see elephants,monkeys,dogs and other animals doing quite skillful things．Perhaps you have seen them on the television or in a film．If you watch closely,you may notice that the trainer always gives the animal a piece of candy or a piece of fruit as a reward．The scientists say that many different animals may be trained to do a number of simple jobs if they know they will get a reward for doing them.
Of course,as we know,dogs can be used to guard a house,and soldiers in both old and modem times have used geese to give warning by making a lot of noise when a stranger or an enemy comes near．But it may be possible to train animals to work in factories．In Russia,for example,pigeons which are birds with good eyesight,are being used to watch out for faults in small steel balls that are being made in one factory．When the pigeon sees a ball which looks different from others,it touches a steel plate with its beak．This turns on a light to warn people in the factory．At the same time a few seeds are given as a reward．It takes three to five weeks to train a pigeon to do this and one pigeon can inspect 3 000 to 4 000 balls an hour.
Apes have been used in America in helping to make cars,and scientists believe that these large monkeys may be one day gather crops and even drive trains.

The trainer usually gives the animal a piece of candy or fruit__.

A.when it is hungry
B.before it plays a trick
C.when it starts to play a trick
D.after it has done the trick