The struggle for women's political rights in the United States has deep and complex roots, says historian Kate Lemay.

历史学家凯特· 勒梅表示，在美国争取女性政治权利的斗争有着深刻而复杂的根源。

Algebra In the field of algebra, Gauss proved the fundamental theorem of algebra, which states that every non-constant polynomial equation has at least one complex root.

代数 在代数领域，高斯证明了代数基本定理，即每个非常数多项式方程至少有一个复根。

While birds nest among mangrove branches, fish lay eggs amidst their sprawling, complex root systems. Symbiotic sponges and sea squirts protect their host trees from hungry woodboring crustaceans.

鸟儿在红树林的树枝间筑巢，鱼儿则在它们庞大而复杂的根系中产卵。共生的海绵和海鞘保护它们的寄主树免受饥饿的钻木甲壳类动物的侵害。