在函数y=5x-2中,自变量x的取值范围是______.

题型:填空题

问题:

在函数y=
5
x-2
中,自变量x的取值范围是______.
考点:函数值
题型:填空题

汽车驾驶员手册规定:具有良好刹车的汽车,以v1=80 km/h的速度行驶时,应在x1=56 m的距离内被刹住;以v2=48 km/h的速度行驶时,应在x2=24 m距离内被刹住。假设两种情况下刹车后的加速度大小相同,驾驶员在这两种情况下的反应时间相同,则反应时间约为[ ]

A.0.5 s

B.0.7 s

C.0.9 s

D.1.2 s

题型:填空题

生鲜肉的种类主要有()、冷鲜肉。

题型:填空题

You should allow your children the space to voice their opinions,______they are different from your own..

A.until

B.even if

C.unlness

D.as though

题型:填空题

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 largest 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.

1. The underlined word "longevity" in the second paragraph probably refers to "_____".[ ]

A. health

B. long life

C. ageing

D. effect

2. The text mainly talks about _____. [ ]

A. men's heart cells

B. women's ageing process

C. the gender difference

D. hearts and long life

3. 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

4. If you want to live longer, you should _____. [ ]

A. enable your heart to beat much faster

B. find out the reason for ageing

C. exercise regularly to keep your heart healthy

D. prevent your cells from being lost

题型:填空题

下列各句句式与其他三项不同的是 [ ]

A.夫晋,何厌之有?            

B. 缙绅而能不易其志者 

C.野语有之曰……我之谓也      

D. 惟命是从 

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