25选 C啊, For example, G10 garnets, a type of garnet typically found in (45) diamond-rich pipes, are lower in calcium and higher in chrome than garnets from barren pipes. Geo- chemists John Gurney showed that garnets with this composition were (50) formed only in the diamond-stability field; G10低Calcium高Chrome,不能说明低Calcium高Chrome一定形成钻石。这里我觉得B钻了逻辑的空子。C .the pipe passed through a diamond-stability field and thus may contain diamonds我觉得C的逻辑严谨一些。 C .the pipe passed through a diamond-stability field and thus may contain diamonds我觉得C的逻辑严谨一些。
[此贴子已经被作者于2006-9-8 16:43:09编辑过] |