跨校专升本，社会专升本，成人自考（双学位的那种...

认识的第二次飞跃指的是（
）

A.由认识到实践
B.由实践到认识
C.由认识到真理
D.由真理到认识

某甲临终订立自书遗嘱，内容是：将其遗产100万元中的50万元给其配偶，25万元给其儿子，25万元给其保姆。依据我国《继承法》的规定，甲的遗嘱（　　）。

A.无效

B.有效

C.部分无效

D.效力待定

The dog has always been considered man′s best friend.Always noted for being particularly?faithful in watching over children,he also has his place by the fireside,in the cow pasture,on the?sheep range(放牧区),and beside the hunter in forest.He is easy to train,works hard,and often?performs astonishing feats.And in the frozen polar regions he was once the principal motive power,before being lately displaced by the plane and helicopter.
Because he howls or whines in the presence of impending death,the dog was once thought to?have supernatural powers and believed to be capable of seeing gods and ghosts invisible to men.Actually,the.basis for these beliefs lies in the hound′s sensibility to people′s feelings and his superior?hearing ability and sense of smell,which enable him to detect signs hidden from human observation.His record of saving lives is outstanding,for he often gives warning of fire and other dangers not noticed by his master.
The dog′s major contribution,however,has been to medical research.Both his diet and his?structure are comparable to those of the human being,and so he has been the subject Of countless?demonstrations and experiments.Open-heart surgery has been made possible largely because of the?dog.But his sacrifice has repaid his own species as well by safeguarding it from rabies(狂犬病),distemper,and other diseases.

In the polar regions,the dog mainly__________.

A.carried supplies
B.provided companionship
C.tracked prey
D.herded caribou（驯鹿）