问题 选择题

下列情况:①氢气燃烧②煤燃烧③飞机的尾气④工业的废气排放⑤燃放鞭炮⑥环卫工人在街边烧树叶,其中可以造成空气污染的有(   )

A.①②③

B.②④⑤⑥

C.①④⑤⑥

D.②③④⑤⑥

答案

D

题目分析:①氢气燃烧生成水,不会造成污染;②煤燃烧会产生SO2、一些粉尘等,造成空气污染;③飞机尾气主要成分为NO、CO等,会造成空气污染;④工业废气的排放会造成空气污染;⑤燃放鞭炮会产生NO等气体,会造成空气污染;⑥焚烧树叶会产生有害气体CO和灰尘,会造成空气污染;故②③④⑤⑥可造成空气污染,答案为D。

点评:环境污染日趋严重,要保护环境,树立保护环境人人有责的理念.

单项选择题

While the ripples of America’s subprime-mortgage crisis have spread far and wide, Latin America—a place long associated with financial disaster—has remained improbably calm. Banks have reported no unpleasant surprises. Brazil and Peru have been blessed with coveted investment-grade ratings. Surprisingly, perhaps the fleetest country of all has been Argentina. Since it emerged from the financial crisis of 2001-02, it has been one of the world’s fastest-growing economies. It is expected to expand faster than most of its neighbors again this year.

Quite simply, it barely has any credit. Back when its economy virtually collapsed, the country suffered a run on its banks, followed by a freeze on withdrawals, and a massive currency devaluation. As a result, bank lending to the private sector shrivelled, from 23.8% of GDP in 2000 to 10.8% in 2003. Since then, it has rebounded to a piddling 13% ; by contrast, the ratio in Brazil was 36.5% in 2006. Almost all of these loans in Argentina are accessible only on a short-term basis.

Once its recovery began in June 2002, Argentina became a paradise for business. Unemployment of over 20% kept wages down, and the devaluation gave exporters an edge on foreign competitors. The ample productive capacity left idle by the crisis meant firms could expand without making big investments. And the windfall profits reaped by agricultural exporters, thanks to record commodities prices, enabled many of them to finance new projects out of earnings. Hence the economy could grow at almost 9% a year with little need for credit.

But such a lucky confluence of factors could not last. Starting in early 2005 ,.inflation picked up, a sign that the installed capacity was starting to limit output. Salaries and prices for raw materials increased sharply, cutting into profits. And farmers were particularly hard hit when the government nearly doubled the taxes in farm exports. Now, just as companies need to embark on big investments if they are to keep growing, their margins are no longer big enough to pay for the expansion and they need to borrow.

So, the time is ripe for the country’s financial system to recover. But a number of things are in the way. Foremost is Argentina’s business risk. Those in the informal economy (which represents over 40% of GDP) can neither save nor borrow legally, lest they become known to the taxmen. The rest remain cowed by memories of the crisis. Although Argentines have poured their savings into property, fuelling a construction boom, they still hold about four-fifths of their deposits abroad.

Inflation, fuelled by a public-spending binge, state-mandated wage increases, and a cheap currency, is not helping either. No one knows how high it is. The consumer-price index is doctored to keep the official rate below 10%, but private estimates suggest it is near 25%. Without a reliable index of inflation, lending is almost impossible, even for the medium term. And the central bank has kept interest rates ply negative in real terms, encouraging workers to spend their wages rather than to save.

There is no reliable index of inflation, because()

A. the currency is cheap

B. there are different ways to get the index

C. the index have been manipulated by the government

D. the central bank has kept rates low

多项选择题