问题 选择题

下列命题正确的是

A.同一边上两个角相等的梯形是等腰梯形;

B.一组对边平行,一组对边相等的四边形是平行四边形;

C.如果顺次连结一个四边形各边中点得到的是一个正方形,那么原四边形一定是正方形。

D.对角线互相垂直的四边形面积等于对角线乘积的一半。

答案

答案:D

根据所学四边形的知识判断:

A、同一底上两个角相等的梯形是等腰梯形.故错误;

B、一组对边平行且相等的四边形是平行四边形.故错误;

C、如果顺次连接一个四边形各边中点得到的是一个正方形,那么原四边形是任意四边形.故错误;

D、对角线互相垂直的四边形面积等于对角线乘积的一半.正确;

故选D.

问答题
单项选择题

It is not just Indian software and "business-process outsourcing" firms that are benefiting from the rise of the internet. Indian modern art is also on an upward spiral, driven by the aspirations of newly rich Indians, especially those living abroad, who use the internet to spot paintings and track prices at hundreds of gallery and auction websites. Prices have risen around 20-fold since 2000. particularly for prized names such as Tyeb Mehta and F.N. Souza.

There would have been "no chance" of that happening so fast without the internet, says Arun Vadehra, who runs a gallery in Delhi and is an adviser to Christie’s, an international auction house. He expects worldwide sales of Indian art, worth $ 200million last year, to double in 2006. It is still a tiny fraction of the $ 30 billion global art market, but is sizeable for an emerging market.

For newly rich--often very rich--non-resident Indians, expensive art is a badge of success in a foreign land." Who you are, and what you have, are on your walls," says Lavesh Jagasia, an art dealer in Mumbai. Indian art may also beat other forms of investment. A painting by Mr. Mehta that fetched $ 1.58 million last September would have gone for little more than $ 100 000 just four years ago. And a $ 22million art-investment fund launched in July by Osian’s, a big Indian auction house, has grown by 4.1% in its first two months.

Scant attention was paid to modern Indian art until the end of the 1990s. Then wealthy Indians, particularly those living abroad, began to take an interest. Dinesh Vazirani, who runs Saffronart, a leading Indian auction site, says 60% of his sales go to buyers overseas.

The focus now is on six auctions this month. Two took place in India last week; work by younger artists such as Surendran Naif and Shibu Natesan beat estimates by more than 70%. Sotheby’s and Christie’s have auctions in New York next week, each with a Tyeb Mehta that is expected to fetch more than $ 1 million. The real question is the fate of other works, including some by Mr. Souza with estimates of up to $ 600 000. If they do well, it will demonstrate that there is p demand and will pull up prices across the board. This looks like a market with a long way to run.

According to the text, the fortune of such works as Mr. Souza’ s can exert an influence on ()

A. the creation of modern art

B. production of younger artists

C. the p rejection of market policy

D. the value of Indian modern art