Even at a distance, odors can warn us of2 trouble - spoiled food, leaking gas, or fire.

即使还隔着一段距离，气味就能提醒我们注意很多麻烦：变质的食物，煤气泄漏，或是火灾。

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In this paper, two infinite families of2 - tight optimal double loop networks are found.

找到两个2紧优双环网络的无限族。

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