Endangered species are plant and animal species (36)___

Câu hỏi :

Read the following passage and mark the letter A, B, C or D on the answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 36 to 40.

Endangered species are plant and animal species (36)___ are in danger of extinction. The primary causes of species extinction are habitat destruction, commercial (37)  and pollution.The drainage of wetlands, cutting of forests, urbanization and road and dam construction have destroyed or seriously damaged natural habitats.

Plant and animal extinction leads to a loss of biodiversity. Maintaining biodiversity is important for us in many ways. Humans depend on species diversity to have food, clean air and water, and fertile soil for agriculture. In addition, we benefit greatly from many medicines and (38)         products that biodiversity provides.   (39)       , different conservation efforts have been (40)_____ in order to save endangered species.