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Plant Self-defense Plants may appear to be helpless in the face of hungry,toothy animals but many plants have evolved interesting systems of self-defense. Coarse meadow grasses are a good example. If you run your finger along a blade of coarse grass,
发表于:2018-12-31 / 阅读(45) / 评论(0)
英语听力文摘 English Digest
英语听力文摘 English Digest