The hard outer shell of sea urchins are commonly called tests.

Afterward, the seas became far more complex with mobile creatures such as snails, urchins and crabs.

此后, 海洋生物逐渐丰富起来,海洋里生长着大量移游生物,比如腹足类 、 海胆类和蟹类.

Scientists have long used sea urchins to study fertilization and early development in humans.

科学家们一直用海胆来研究受精卵和人类早期形态.

He compares sea urchins to rabbits and other grazers found on land.

把海胆与兔子和其它陆生食草动物作个比较.

Sea urchins can also be used by scientists to detect toxic chemicals.

海胆还可以用于探测有毒化学成分.

He knew upperclassmen could have a big effect on younger students.

他知道高年级学生对低年级的学生影响很大.

Today, private undertakings in the Red areas are small in scale.

目前私人经济在红色区域是取着小规模经营的形式.

County has always attached importance to public health undertakings.

我县一贯重视卫生事业.

There is always the secret vote. I don't think we could make any written undertakings.

秘密经费总是有的. 我想我们不能写任何书面保证.

In 1962 there more than 80 undertakings in western Germany engaged in the gypsum industry.

1962年在西德有80家以上的企业从事石膏工业.

The more developed culture and education and health undertakings.

文教卫生事业较为发达.

Scientific and technological undertakings made new achievements.

科学研究和技术开发取得新的成果.

MOFCOM shall not force the exporter to enter into price undertakings.

商务部不得强迫出口经营者作出价格承诺.

Unless one has an unbreakable steel-like spirit, one cannot accomplish momentous undertakings.

缺乏钢铁般的精神, 就不能干大事.

Public undertakings shall be designated for the service of the general public.

公用事业要致力于服务大众.

He often dresses in tweeds.

他常穿斜纹软呢服装.

The gentleman was dressed in Scottish tweeds.

这位绅士穿着以苏格兰粗呢制成的衣服.

He is usually dressed in tweeds.

他常穿花呢服装.

They wove wool into tweeds.

他们将羊毛织成粗呢.

She was sensibly dressed in tweeds.

她穿着实用的苏格兰粗呢制衣服.

Tweeds are the big thing this fall.

(粗)花呢服装是今秋风行的服装.