美国科学60秒 SSS 2013-06-27
时间：2018-12-24 作者：英语课 分类：Scientific American(六)月
Flawless pearls are among the most symmetrical spheres biological organs. But do they get so round? Turns out they turn. Pearls and mollusks such as oysters 2 create so-called pearls acs around intrusive 3 pieces of grit 4. The sac coat the yelten with the layer smooth biker also known as mother of pearls. The growing pearls rotate itself which allows the biker to deposit even they over its surface.By examining pearls under influences and scanning electronic microscope, researcher discovered that the surface actually has soft tooth texture 5. As the mollusk 1 moves, the pearls flaw so to the next tiny tooth. The works is published in the Journal Lanier. A pearl' motion influences its niker coverage 6 and not its finally shape. Depending on its surface pattern, it might turn in a single direction to create a drop or ring, or rotate more freely to form sphere, if defect prevents this motion, the final product will be shapeless. The resulting asymmetrical 7 pearls is doomed 8 to be booed.
- I swear I have never seen such a mollusk with thorns all over its body.我敢发誓我从来没有见过这种全身长满棘刺的软体动物。
- The colour varies with the mollusk and its environment.颜色因母体及其环境的不同而异。
- We don't have oysters tonight, but the crayfish are very good. 我们今晚没有牡蛎供应。但小龙虾是非常好。
- She carried a piping hot grill of oysters and bacon. 她端出一盘滚烫的烤牡蛎和咸肉。
- The cameras were not an intrusive presence.那些摄像机的存在并不令人反感。
- Staffs are courteous but never intrusive.员工谦恭有礼却从不让人感到唐突。
- The soldiers showed that they had plenty of grit. 士兵们表现得很有勇气。
- I've got some grit in my shoe.我的鞋子里弄进了一些砂子。
- We could feel the smooth texture of silk.我们能感觉出丝绸的光滑质地。
- Her skin has a fine texture.她的皮肤细腻。
- There's little coverage of foreign news in the newspaper.报纸上几乎没有国外新闻报道。
- This is an insurance policy with extensive coverage.这是一项承保范围广泛的保险。
- Most people's faces are asymmetrical.多数人的脸并不对称。
- Folds may be gentle and symmetrical,or sharp and asymmetrical.褶皱可以是平缓而对称的，也可以是陡峭而非对称的。