An earth scientist has rejigged the periodic table1 to make chemistry simpler to teach to students.

　　____1____But Bruce Railsback from the University of Georgia says he is the first to create a table that breaks with tradition and shows the ions of each element rather than just the elements themselves.

　　“I got tired of breaking my arms trying to explain the periodic table to earth students,”he says, criss-crossing his hands in the air and pointing to different bits of a traditional table.____2____But he has added contour lines to charge density, helping to explain which ions react with which.

　　"Geohemists just want an intuitive sense of what's going on with the elements," says Albert Galy from the University of Cambridge4,____3____

　　____4____He explains that sulphur, for example , shows up in three different spots — one for sulphide, which is found in minerals, one for su1phite, and one for su1phate, which is found in sea sa1t, for instance.

　　He has also inc1uded symbols to show which ions are nutrients，and which are common in soi1 or water.____5____

　　練習(xí)：

　　A. There have been many attempts to redesign the periodic table since DmM Mendeleev2 drew it up in 1871.

　　B. Railsback has still ordered the elements according to the number of protons they have.

　　C. “I imagine this would be good for undergraduates.”

　　D. Railsback has listed some elements more than once.

　　E. And the size of element’s symbol reflects how much of it is found in the Earth’s crust.

　　F. The traditional periodic table was well drawn.

　　答案與題解：

　　1.A　文章講重新設(shè)計(jì)元素周期表。第一段講了一位地球科學(xué)家已經(jīng)調(diào)整元素周期表,使得教學(xué)生化學(xué)時(shí)更容易些。接著是第二段。第一句是空白,需要填入。接下來(lái)的一句話是這么說(shuō)的:佐治亞大學(xué)的Bruce Railsback說(shuō)他是第一個(gè)創(chuàng)造出這樣一個(gè)表的人,他突破了傳統(tǒng),顯示了每個(gè)元素的離子而不只是元素本身。A的意思是:自從1871年門捷列夫畫出元素周期表以來(lái),許多人試圖重新設(shè)計(jì)周期表�！暗谝粋�(gè)”這個(gè)信息很重要。按照從一般到具體的行文規(guī)律,前一句話應(yīng)當(dāng)是一般性的描述。A符合這個(gè)條件。

　　2.B　第三段的第一句話是這么說(shuō)的在給學(xué)生解釋元素周期表時(shí)我的手臂都要斷了他這么說(shuō)時(shí)在空中來(lái)回交叉雙手,指點(diǎn)傳統(tǒng)周期表中不同的元素。這一句話是講Bruce Railsback重新制作元素周期表的原因。從主題發(fā)展來(lái)看,這句話似乎跟上文連不上,但這是一篇報(bào)道,插入了一些背景信息和其他人的評(píng)論。從第二段的最后一句話來(lái)看，B比較合適,因?yàn)槎际侵v元素。B說(shuō)的是:RailSback仍然按照元素所有的質(zhì)子數(shù)排列元素。注意:D也是講元素。但是B中有still(仍然)這個(gè)詞,它是銜接第二段的最后一句話的。

　　3.C　第四段是劍橋大學(xué)的Albert Galy對(duì)Bruce Railsback重新創(chuàng)造的元素周期表的評(píng)論。評(píng)論常常用原話。引號(hào)表明C是原話。

　　4.D　第五段需填入主題句。主題句常常是概括性的。從第五段提供的信息來(lái)看,sulphur(硫黃)這個(gè)元素在三個(gè)地方出現(xiàn),因此D是正確的。D說(shuō)的是:有些元素Railsback列了一次以上。

　　5.E　六段的第一句講到了符號(hào)。E也是講符號(hào),其他的選項(xiàng)都沒(méi)有講,因此應(yīng)選E。