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[单选题]
请选择表达最为正式的词语填在空白处。The scientists asked 200 passersby to estimate the angle of a set of stairs, and another 200 to do the same for an escalator—which, of course, requires no effort to __________.
A.go up
B.rise
C.climb
D.ascend
提问人:网友qd78560
发布时间:2022-01-07