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问题 单项选择题 A型题

关于β受体阻滞剂对心电图影响的描述，错误的是（）。

A.可减慢窦性心率

B.可延长PR间期

C.可延长QT间期

D.对P波、QRS波群无影响

E.可导致不同程度的房室传导阻滞

答案

参考答案：C

完形填空

A rich landowner decided to leave possessions to one of his two sons. As he lay on the deathbed, he called the two young men to him     小题1:    the break of dawn and even before the cock could crow (鸣叫). He then said, “I will leave all my wealth to the one     小题2:    can best fill this room. It was in this room     小题3:     I made plans on how to build up my fortune. Not an inch must     小题4:    (leave) uncovered. As I am getting     小题5:   (weak) by the hour you both must come back by midnight.” He handed them a small piece of silver and an empty bag to put their purchases in. They both went out and    小题6:    (hurry) came back with their purchases.     小题7:    (bring) the straw, the elder began to spread it about the floor,    小题8:     far from filling the room. It did not even cover half the space. “This is no use, son,” said the father, “and let me see how    小题9:     brother fills the room.” The younger son took     小题10:    his bag a large candle, set it on the table in the centre of the room and lit it. A brilliant bright light filled up the whole room. The father was delighted and exclaimed, “Son, I am sure you will use the wealth well.”
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选择题

对人来说，决定子代的性别主要是（　　）

A．卵细胞

B．精子

C．性激素

D．促性腺激素
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