一个人专升本考试能考几次？

下列哪些是左室肥大的诊断标准 （　　）

A.V5导联的R波+V1导联的S波>3．5mV(男性)

B.QRS波群时限>0．16s

C.I导联的R波+Ⅲ导联的S波>2．5mV

D.电轴左偏O～-30°

E.ST段压低超过-0．05mV，T波低平或倒置

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.

The article does not say whether the scientists′experiments with dogs have__________.

A.benefited animals other than dogs
B.served man
C.helped other dogs
D.contributed to medical knowledge

在经济危机和萧条阶段，资本主义国家向私人企业注入一部分国有资金以维持其生存的经济行为属于

A.建立资本主义国有经济和国有企业的一种方式
B.国家和私人资本在企业内部结合的一种方式
C.国家和私人资本在企业外部结合的一种方式
D.资本主义国家实行经济计划的一种方式

设Y=xsinx，求Y′．