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【单选题】压力机操作时采用手用工具(如夹具、镊子)可以代替人手伸进危险区送取物料。配备了手用工具，__________安全装置。
A.
可以取代
B.
不可取代
C.
可设置可不设置
D.
多余设置
【单选题】The Grand Canyon Standing on the rim of the Grand Canyon(大峡谷), gazing across this giant wound in the Earth’’s surface, a visitor might assume that the canyon had been caused by some ancient convulsion...
A.
it was caused by some ancient convulsion
B.
its presence is an embarrassment to the state of Colorado
C.
it looks like an injury on the Earth’s surface
D.
it has caused many visitors to injure themselves