2. 倒置的；颠倒的

1. 用……遮盖

24.　 Let’s do some exercise: stand straight, holding a tall, ____________ (稳定的；稳固的) object for balance.

23.　 Heat ______________ (容量；性能) is the amount of energy it takes to raise the temperature of a substance by one degree centigrade.

22.　 Estuaries are also important because they absorb nutrients and ______________ (污染物质) from water coming from inland sources, thus cleaning our water.

21.　 Finally, estuaries provide both ________________ (娱乐；消遣) and education for human beings.

20.　 The diversity of life in estuaries is incredible ---- birds, fish, marine mammals, shellfish and other species all come here to live, feed and ________________ (繁殖).

19.　 This mixing of fresh and salt water creates a ______________ (独特的；唯一的) environment filled with life of all kind.

18.　 __________ (潮；潮水) provide energy for the ecosystems.

17.　 Animals can enjoy all the ______________ (利益) of the oceans without having to face many of the dangers.