carner study had identified the mineral in several 17th century works bbrandt,but researhers had nt comr it orkm the iRnaisse nil the new nysis Plmriteform when lead oxidesP)mnewith oil,Mixing these two substances is a tehniqe that laterartistsikebrandt used to help the paint dry,Gilles Wallez,anthor of the lateststdysaid."Each time you discover something on his processes,you diseovered that hewas clearly ahead of his time."The Mona Lisa,like many other paintings from the 16th century,was createdon a wood board that required a thick base layer.The researchers believe thatLeonardo had made his mixture of lead oxide powder with oil to produce the thickcoat of paint needed for the first layer,while unknowingly creating the rarecompound.Nowadays,researchers aren't allowed to take samples from the masterpiece,which is displayed at the Louvre Museum and is protected behind glass.Using a 2007sample that had been taken from an area of the artwork just behind the frame,ahowever,scientists were able to analyze the paint by using a high-tech machinenscalled a synehrotron."These samples have a very high cultural value,"Wallez said.an"Yoford to take big smplea painting,isthe best waato analyze them.”28.What is the finding of the new study about Da Vinci?ndA.He used to work as a chemist.heB.He did experiments with Mona Lisa.heC.He applied techniques ahead of his time.t。D.He was born rlier than previously thought.英语试题(六)第8页(共16页)