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____
练习：
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.
答案与题解：
1.A 文章讲重新设计元素周期表。第一段讲了一位地球科学家已经调整元素周期表,使得教学生化学时更容易些。接着是第二段。第一句是空白,需要填入。接下来的一句话是这么说的:佐治亚大学的Bruce Railsback说他是第一个创造出这样一个表的人,他突破了传统,显示了每个元素的离子而不只是元素本身。A的意思是:自从1871年门捷列夫画出元素周期表以来,许多人试图重新设计周期表。“第一个”这个信息很重要。按照从一般到具体的行文规律,前一句话应当是一般性的描述。A符合这个条件。
2.B 第三段的第一句话是这么说的在给学生解释元素周期表时我的手臂都要断了他这么说时在空中来回交叉双手,指点传统周期表中不同的元素。这一句话是讲Bruce Railsback重新制作元素周期表的原因。从主题发展来看,这句话似乎跟上文连不上,但这是一篇报道,插入了一些背景信息和其他人的评论。从第二段的最后一句话来看，B比较合适,因为都是讲元素。B说的是:RailSback仍然按照元素所有的质子数排列元素。注意:D也是讲元素。但是B中有still(仍然)这个词,它是衔接第二段的最后一句话的。
3.C 第四段是剑桥大学的Albert Galy对Bruce Railsback重新创造的元素周期表的评论。评论常常用原话。引号表明C是原话。
4.D 第五段需填入主题句。主题句常常是概括性的。从第五段提供的信息来看,sulphur(硫黄)这个元素在三个地方出现,因此D是正确的。D说的是:有些元素Railsback列了一次以上。
5.E 六段的第一句讲到了符号。E也是讲符号,其他的选项都没有讲,因此应选E。
