响墩按危险品妥善保管, 谨防高温和潮湿, 否则(), 应严格管理。 响墩有效期为两年,每年必须抽样检查一次。使用前用手拿起摇晃,炸药哗哗响时,说明没有受潮,还()使用。响墩是(),不要用锤在钢轨上敲打,否则容易把铁皮炸碎,飞起伤人。()要用站内调车机试验,禁止用锤敲打
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频繁移动地点的作业由现场防护员手持停车手信号防护()
Formulated in 1823, the Monroe Doctrine asserted that the Americas were no longer open to European colonization.()
A. emphatically stated
B. belligerently(aggressively) argued
C. accentuated(emphasize)
D. entreated 恳求 (implore, plea, invoke )
The first paper was made from the bark of the mulberry tree.()
A. dried wood
B. outer covering
C. syrup(sirup)
D. root