We lowered the rating on Greek sovereign debt to BBB, and spreads stayed just below levels for AA rated bonds. But when we lowered the rating to BB, we saw spreads hit CCC bond levels.

我们将希腊主权债信评级下调至BBB级别时，其收益率仍维持在比AA级债券略低的水平，可当我们进一步下调至BB级时，其收益率一下子飙升至CC C级债券的水平。

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If scientists are working with a mixture of two cell types, for example a and B, they end up with many AA and BB pairings, as well as the desired AB match.

如果科学家处理的是两种类型的细胞的混合物，例如A和B，他们最终会以AA和BB配对，以及所需的AB配对。

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BB may rescind the Agreement if AA fails to reach the minimum annual purchase quantity without any compensation.

如果AA没有达到最低年采购量，BB可以解除本协议，并且没有任何赔偿。

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