单选题

　　1.【填句补文】“Geochemists just want an intuitive sense of what's going on with the elements,” says Albert Galy from the University of Cambridge ________.

　　A.An earth scientist has rejigged the periodic table(元素周期表)to make chemistry simpler to teach to students.

　　B.The traditional periodic table was well drawn.

　　C.“I imagine contour lines would be good for undergraduates.”

　　D.But he has added contour lines to charge density, helping to explain which ions react with which.