| A.wasted land used to be wetlands |
| B.people didn’t know the importance of wetlands before |
| C.wetlands used to be left undisturbed |
| D.wetlands can be used for building |
| A.They absorb extra water from storms. |
| B.They become large or small in size. |
| C.They absorb pollutants and dissolve them. |
| D.They are made of soft soil. |
| A.Two. | B.Three. | C.Four. | D.Five. |
| A.the threat to wetlands |
| B.the protection of wetlands |
| C.the development of wetlands |
| D.the importance of wetlands |
| A.some wetlands can be used to build cities or towns |
| B.wetlands in the world are disappearing fast |
| C.wetlands play an important role in the ecosystem |
| D.wetlands are especially important to wildlife |