1·How did the dolphin's clicks get transmitted from its air-filled nasal sacs into the ocean water?
海豚发出的滴答声是如何从充满空气的鼻囊传播到海水中的呢？
2·"Cells are just watery sacs," says Niklason.
细胞就是个水囊。
3·Bird feathers and reptile scales contain melanosomes-tiny sacs holding varieties of the pigment melanin. Many paleontologists suspected that dinosaur feathers also contained melanosomes.
因为鸟类羽毛和爬行动物的鳞片都包含黑素体——这是一种微小的囊状结构，其中包含了各种各样的黑色素，于是很多古生物学家开始怀疑恐龙羽毛是否也含有黑素体。
4·Different glands make different sorts of silk to be used for purposes including the manufacture of egg sacs, lining shelters and constructing webs.
不同的腺体制造不同种类的蛛丝，其作用包括制造卵囊﹑划定居所﹑编织蛛网等许多方面。
5·In addition, more information about the cause of monozygotic twins could be collected in the future by a straightforward check of the Numbers of placentas and sacs when the babies are born.
另外，将来有关单卵双胞胎原因更多的信息可以直接通过出生后核对胎盘和羊膜囊的数目来获得。