单项选择题 中国外汇交易中心显示的人民币对主要币种的汇率中间价如下表所示：2020年1月2日至5月28日期间人民币对美元汇率的变动可能带来的影响是（　　）。

单项选择题 中国外汇交易中心显示的人民币对主要币种的汇率中间价如下表所示：2020年1月2日相比，5月28日人民币对美元的变动情况是（　　）。

未知题型 回答{TSE}题： Ants as a Barometer of Ecological Change At picnics, ants are pests. But they have their uses. Inindustries such as mining, farming and forestry, they can help gauge the healthof the environment by just crawling around and being antsy. It has been recognized for decades that ants-which are highlysensitive to ecological change can provide a near-perfect barometer of thestate of an ecosystem. Only certain species, for instance,will continue tothrive at a forest site that has been cleared of trees.46__________And stillothers will move in and take up residencE.By looking at which species populate a deforested area,scientists can determine how 'stressed' the land is. 47__________Ants are used simply becausethey are so common and comprise so many species. Where mine sites are being restored, for example, some antspecies will recolonize the stripped land more quickly than others. 48__________Australianmining company Capricorn Coal Management has been successfully using antsurveys for years to determine the rate of recovery of land that it isreplanting near its German Creek mine in QueenslanD.Ant surveys also have been used with mine-site recoveryprojects in Africa and Brazil, where warm climates encourage dense and diverseant populations. 'We found it worked extremely well there,' saysJonathan Majer, a professor of environmental biology. Yet the surveys areperfectly suited to climates throughout Asia, he says, because ants are socommon throughout the region. As Majer puts it:'That's the great thingabout ants. ' Ant surveys are so highly-regarded as ecological indicators thatgovernments worldwide accept their results when assessing the environmentalimpact of mining and tree harvesting. 49__________Why not? Because many companies can't afford the expense or thelaboratory time needed to sift results for a comprehensive survey. The coststems, also, from the scarcity of ant specialists,50__________ A.This allowed scientists to gauge the pace and progress ofthe ecological recovery. B.Yet in other businesses, such as farming and propertydevelopment, ant surveys aren't used widely. C.Employing those people are expensivE.D.They do this by sorting the ants, counting their numbers andcomparing the results with those of earlier surveys. E.The evolution of ant species may have a strong impact on ourecosystem. F.Others will die out for lack of fooD.{TS} 46__________