12. They are those that live on or depend on the bottom like the starfish, those that move ________ of water currents and those that are carried along by the currents.
A. independenceB. independentC. independentlyD. dependent
13. Some marine animals are _________ to humans.
A. dangerB. dangerousC. endangeredD. dangerously
14. You may be surprised at the large ----------- of animals that live in the sea.
A. variety B. variously C. various D. vary
15. Community police have made a very positive ______ to crime prevention.
A. contributeB. contributiveC. contributionD. contributively
16. They are investigating the ______ disappearance of a young woman.
A. mysteryB. mysteriousC. mysteriouslyD. mysteries
17. By the age of eighteen he was completely ______ of his parents.
A. dependenceB. dependentlyC. dependentD. depend
18. The ______ of the seabed is being carried out.
A. investigateB. investigativeC. investigationD. investigating
19.For centuries, people have been challenged by the ___________ that lie beneath the ocean.
A. mysteryB. mysteriousC. mysteriouslyD. mysteries
20.Dolphin population is at stake due to the _______of their habitats and accidental entrapment in fishing nets.
A. polluteB. pollutiveC. pollutionD. pollutants
21. Nairobi National Park is Kenya’s smallest park, but you may be surprised at the large ______ of animals that live there.
A. varyB. varietyC. variousD. variously
22. Visitors, especially children, can go to Cuc Phuong National Park to learn how to recognize the ---------species of animals and plants.
A. differB. differenceC. differentD. differently
23. This national park is _____ because it has plants and animals from both tropical and temperate zones.
A. specially B. special B. specialize D. specialization
24. The giant panda is in danger of becoming extinct. It is an -------species.
A. dangerousB. dangerously C. endanger D. endangered
25. Trees, grasses, and other plant life play an important part in the _______ circulation of water.
A. natural B. natureC. naturallyD. naturalize
26. Without plants, most water would run off as soon as it falls, taking away ______ soil.
A. valueB. valuableC. valuablyD. values
27. The earth is being threatened and the future looks _______.
A. badB. badlyC. badnessD. worsen
28. Man is _______ doing harm to the environment.
A. constancyB. constantC. constantlyD. constants
29. A campfire near a heap of leaves may _____ cause a forest fire.
A. easeB. easyC. easilyD. eases
30. A gulf is a term that refers to the ________ of different kinds of animals and plants which make a balanced environment.
A. existB. existenceC. existentD. existed
