虫体表面神经纤维成对并行，斜行交叉，构成表面神经网。

The nerve fibers on body surface in pairs and parallel are diagonal and cross to form a nerve network on body surface.

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虫体表面神经纤维成对并行，斜行交叉，构成表面神经网。

The nerve fibers on body surface in pairs and parallel are diagonal and cross to form a nerve network on body surface.

youdao