潜孔钻机是利用潜入孔底的冲击器与钻头对矿物进行冲击破碎,其主要特点是()。 A.一次

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问题:

潜孔钻机是利用潜入孔底的冲击器与钻头对矿物进行冲击破碎,其主要特点是()。

A.一次成孔

B.排渣方便

C.结构简单、造价低廉

考点:露天钻机考试露天钻机考试题库
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加工硬化既可以提高钢的强度。还可以提高钢的塑性。()

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阅读理解

     Ten years ago, Pierre Omidyar, a software engineer working in California’s Silicon Valley, began

thinking about how to use the internet for a trading system in which buyers and sellers could establish

a genuine market price. Over a long holiday weekend he wrote the computer code. At first, a trickle

of users arrived at his website-including his girlfriend, who traded PEZ candy dispensers. By the end

of 1995, several thousand auctions had been completed and interest in eBay was growing. And it grew

and grew. From this modest beginning, eBay has become a global giant, with around 150m registered

users worldwide who are set to buy and sell goods worth more than $40 billion this year.

     The remarkable tale of eBay’s growth points to some important lessons for any business trying to

operate online-and today that includes, one way or another, most firms. The commercial opportunities

presented by an expanding global web seem almost limitless. But the pace of change is rapid, and so

is the ferocity(激烈)of competition. To succeed, firms need agility(灵活), an open mind and the

ability to reinvent themselves repeatedly. Most of all, they need to listen carefully to their customers,

paying close attention to what they do and don’t want.

     Such qualities, of course, would be valuable in any kind of business. Yet for online firms they are

not a luxury, but necessary for mere survival. This is true for a variety of reasons. The internet is not

only growing, but changing rapidly-which, in turn, changes the rules of the game for any business

relying on it. The barriers to entry are still low compared with those for most offline businesses,

which means that just keeping track of your existing rivals is not enough. These may not represent the

greatest competitive threat tomorrow or the next day. That could come from a number of

directions-a firm in a different type of online business; one that does not yet exist; or even from one

of your own customers. On top of all this, the behavior of many consumers is constantly changing

as well, as individuals discover new ways to shop and interact with each other via the web.

     All these factors make the internet a dangerous place to do business, as well as one full of

promise. eBay’s history demonstrates both of those things. It is probably safe to say that nothing

like eBay could have existed without the internet-or could have grown so fast. Even though there have

been signs of the firm’s blistering(快速的) pace slowing a bit in America, its most “mature” market,

there remain vast opportunities overseas, particularly, some argue, in China. Meg Whitman, eBay’s

chief executive, believes the company is still only at the beginning of what it could achieve.

1. What is the purpose of the first paragraph?

A. To introduce the founder of eBay and his girlfriend.

B. To demonstrate how clever the founder of eBay is.

C. To show how eBay started and has grown.

D. To introduce eBay to people.

2. Which of the following best summarizes Pierre Omidyar’s intention with regard to eBay?

A. To set up a global internet business.

B. To allow people to freely buy and sell on the internet at acceptable prices.

C. To set up a mechanism on the internet to allow people to trade at true market prices.

D. To se up a business mechanism for his girlfriend.

3. Which of these is it NOT necessary for a company selling on the internet to do?

A. Have the most competitive price for each of their online products.

B. Be able to change to suit the prevailing(流行的,优势的)market conditions.

C. Be prepared to consider all options and alternatives.

D. Have a good idea of what their customers do not want.

4. What does “barriers to entry are still low compared with those for most offline businesses”

       in paragraph 3 mean?

A. It is easier to set up an internet business than a conventional one.

B. Internet trade is growing faster than traditional business sector.

C. It is cheaper to set up an internet business than a traditional one.

D. Companies generally prefer to do business online rather than offline.

5. Why does the article conclude that the internet “is a dangerous place to do business”?

A. Because companies that sell online may be unreliable.

B. Because there are no controls on doing business on the internet.

C. Because doing business online is unpredictable.

D. Because even companies like eBay have problems doing business online.

题型:多项选择题

[说明]
八皇后问题是指求解如何在国际象棋8*8棋盘上无冲突地放置八枚皇后棋子。因为在国际象棋里,皇后的移动方式是横竖交叉,所以在任意一个皇后所在位置的水平、竖赢和斜45。线上都不能有其他皇后棋子的存在。一个完整无冲突的八皇后棋子分布称为八皇后问题的一个解。本程序实现了八枚皇后棋子在8*8棋盘上无冲突的放置。
[函数]
#include<math. h>
#include<stdio.h>
#define MAX 8 /*棋子数及棋盘大小MAX*MAX*/
int board [MAX];
/*印出结果*/
void show_result()

int i;
for (i=0;i<MAX;i++)
printf("(%d, %d)",i,board [i]);
printf("\n");

/*检查是否在同一直横斜线上有其他棋子*/
int check_cross (int n)

int i;
for(i=0; i<n; i++)
if( (1) )return 1;

return 0;

/*放棋子到棋盘上*/
void put_chess (int n)

int i;
for (i=0; i<MAX; i++)
board [n] =i;
if( (2) )
if( (3) )show_result();
/*找到其中一种放法了,印出结果*/
else (4) ;



void main()

clrscr();
puts("The possible placements are:");
(5) ;
puts("\n Press any key to quit…");
getch();
return:

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第十位文艺女神

题型:多项选择题

键18×120GB/T1096-2003标记中,键的长度为()

A.18mm

B.102mm

C.112mm

D.120mm

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