问题 选择题

下面是几个不同价态的氮的化合物的相互转化关系(未配平),你认为一定不能实现的是(    )

A.NO2+H2O→HNO3+NO

B.NO+HNO3→N2O3+H2O

C.N2O4+H2O→HNO3+HNO2

D.NH3+NO→HNO2+H2O

答案

答案:D

题目分析:氨气、NO、N2O3、NO2、N2O4以及硝酸和亚硝酸中氮元素的化合价分别是-3价、+2价、+3价、+4价、+4价、+5价和+3价,所以根据氧化还原反应的理论可知,选项ABC都是可以发生的。D中氮元素的化合价不可能都是升高的,答案选D。

点评:该题的关键是准确判断出化合物中氮元素的化合价,然后根据氧化还原反应中化合价升降可以逐一进行判断和验证,有利于培养学生的逻辑推理能力和发散思维能力。

阅读理解

Why do men die earlier than women? The latest research makes it known that the

reason could be that men’s hearts go into rapid decline when they reach middle age.

The latest study of the effects of ageing on the heart has found that women’s longevity may be linked to the fact that their hearts do not lose their pumping power with age.

“We have found that the power of the male heart falls by 20-25 percent between 18 and 70 years of age,” said the head of the study, David Goldspink of Liverpool John Moores University in the UK.

“Within the heart there are millions of cells that enable it to beat. Between the age of 20 and 70, one-third of those cells die and are not replaced in men,” said Goldspink. “This is part of the ageing process.”

What surprises scientists is that the female heart sees very little loss of these cells. A healthy 70-year-old woman’s heart could perform almost as well as a 20-year-old one’s.

“This gender difference might just explain why women live longer than men,” said Goldspink. They studied more than 250 healthy men and women between the ages of 18 and 80, focusing on healthy persons to remove the confusing influence of disease. “The team has yet to find why ageing takes a greater loss on the male heart,” said Goldspink.

The good news is that men can improve the health of their heart with regular exercise. Goldspink stressed that women also need regular exercise to prevent their leg muscles becoming smaller and weaker as they age.

小题1:The text mainly talks about ________. 

A.men’s heart cells

B.women’s ageing process

C.the gender difference

D.hearts and long life小题2:According to the text, the UK scientists have known that ________. 

A.women have more cells than men when they are born

B.women can replace the cells that enable the heart to beat

C.the female heart loses few of the cells with age

D.women never lose their pumping power with age小题3:We can know from the passage that ________.

A.the reason why ageing takes a greater loss on the male heart has been found out

B.scientists are on the way to finding out why the male heart loses more of the cells

C.the team has done something to prevent the male from suffering the greater loss

D.women over 70 could lose more heart cells than those at the age of 20

填空题