[多选题]机械设备须定期（ ），确保技术状态良好，安全防护装置、设施齐全，严禁切除、屏蔽保护性装置。
A.维护保养
B.检查
C.更新

Text 4
Until recently, the common factor in all the science used to figure out if a piece of art was forged was that it was concerned with the medium of the artwork, rather than the art itself. Matters of style and form were left to art historians, who could make erudite, but qualitative, judgments about whether a painting was really good enough to be, say, a Leonardo. But this is changing. A paper in this week’s Proceedings of the National Academy of Sciences by Hany Farid and his colleagues at Dartmouth College in New Hampshire uses statistical techniques to examine art itself—the message, not the medium.
Dr. Farid employed a technique called wavelet analysis to examine 13 drawings that had at one time or another been attributed to Pieter Bruegel the Elder, a 16th-century Flemish painter. He also looked at Perugino’s "Madonna with Child", a 15th-century Italian masterpiece lodged in the college’s Hood Museum of Art. He co
A. Dr. Farid thinks it hard to tell the real works from the imitations
B. Taylor's method may not be applied to other artists' work
C. Real Bruegels used different types of wavelets from those of imitations
D. Curators may soon put forward their own way of examining