正在确认阅读权限…
Why Do Some Insects Walk on Water While Others Sink Immediately?
为什么有些昆虫能在水面行走，而另一些却立刻下沉？
精读先不看文字，完整听一遍。
-
Water striders stay afloat thanks to surface tension—a skin-like film formed by hydrogen bonds between water molecules.水黾依靠水的表面张力漂浮——这种类似薄膜的结构由水分子间的氢键形成。
-
Their long, hydrophobic legs spread weight over a large area without breaking the water’s surface layer.它们细长且疏水的腿将体重分散到较大面积，而不刺破水面。
-
Tiny hairs on their legs trap air, increasing buoyancy and repelling water more effectively than smooth surfaces.腿上的微小刚毛能困住空气，增强浮力，并比光滑表面更有效地排斥水分。
-
In contrast, heavier insects like beetles lack both leg structure and waxy coatings needed to exploit surface tension.相比之下，甲虫等较重的昆虫既无合适的腿部结构，也缺乏利用表面张力所需的蜡质涂层。
-
Even slight oil contamination or soap in water weakens surface tension enough to drown water striders instantly.水中哪怕微量的油污或肥皂也会显著削弱表面张力，导致水黾瞬间沉没。
-
Scientists mimic this natural design to build micro-robots that move silently across polluted water surfaces.科学家仿照这一自然机制，研制出可在污染水面上静音移动的微型机器人。
-
Surface tension also explains why dew drops bead up on spiderwebs instead of spreading flat.表面张力同样解释了露珠为何在蜘蛛网上聚成圆珠，而非铺展成片。
-
Temperature affects surface tension too: colder water holds insects up better than warm water does.温度也影响表面张力：冷水比温水更能支撑昆虫漂浮。
-
This principle helps engineers design waterproof fabrics and self-cleaning surfaces inspired by insect anatomy.这一原理助力工程师设计出受昆虫解剖结构启发的防水织物与自清洁表面。
-
If you gently place a clean steel needle horizontally on still water, surface tension may hold it up—just like a water strider.若将一根洁净的钢针轻轻水平置于静止水面上，表面张力可能使其浮起——就像水黾一样。
精读 · 大约 10 分钟
听 → 读 → 学表达 → 懂 → 今天会说这一句 → 跟读录音 → 自己说一句。
③ 学 · 重点表达
- This principle helps engineers design waterproof fabrics and self-cleaning surfaces inspired by insect anatomy. 这一原理助力工程师设计出受昆虫解剖结构启发的防水织物与自清洁表面。
- Scientists mimic this natural design to build micro-robots that move silently across polluted water surfaces. 科学家仿照这一自然机制，研制出可在污染水面上静音移动的微型机器人。
- Surface tension also explains why dew drops bead up on spiderwebs instead of spreading flat. 表面张力同样解释了露珠为何在蜘蛛网上聚成圆珠，而非铺展成片。
④ 懂 · 选一选
⑤ 今天会说这一句
This principle helps engineers design waterproof fabrics and self-cleaning surfaces inspired by insect anatomy.
⑥ 跟读并录音
This principle helps engineers design waterproof fabrics and self-cleaning surfaces inspired by insect anatomy.
第一版：录下来、回听、再听标准音。系统打分以后再加。
⑦ 说 · 自己来一句
用今天的表达，自己说一句。
例子：This principle helps engineers design waterproof fabrics and self-cleaning surfaces inspired by insect anatomy.
已记下。连续天数以后会显示在课表里。
陈老师指导
课程开发中，敬请期待。成人和孩子都可以先自学听读、精读。
这边的讲解音轨还在做。想先跟着老师走完固定 30 课，可以去陈老师带读社（和自学通行不是同一份会员）。
课程开发中，敬请期待。