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来源:雅诚德英语网
They had found, accidentally, that a rare metal, iridium, suddenly became very abundant exactly at the boundary and then slowly fell away.
他们偶然发现一种稀有金属铱的含量在边界处突然变得很丰富,然后又慢慢地消失了。
They had found, accidentally, that a rare metal, iridium, suddenly became very abundant exactly at the boundary and then slowly fell away.
他们偶然发现一种稀有金属铱的含量在边界处突然变得很丰富,然后又慢慢地消失了。