hold millions of unique life forms that we have yet to discover. Destroying the

　　rainforests is comparable to destroying an unknown planet we have no idea what

　　we're losing. If deforestation continues at its current rate, the world's tropical

　　rainforests will be wiped out within 40 years。

　　1. Virtually all plant and animal species on Earth can be found in tropical

　　rainforests。

　　2. There is not much change in the weather in the tropical rainforests all the year

　　round。

　　3. The largest number of rainforests in the world are located on the African

　　continent。

　　4. Below the canopy level of a tropical rainforest grows an overabundance of

　　plants。

　　5. New tree seedlings will not survive to reach the canopy level unless ______。

　　6. Epiphytes, which form much of the understory of the rainforest, get all their

　　water and nutrients from ______。

　　7. Stranglers are so called because they ______ by blocking the sunlight and

　　competing for the nutrients。

　　8. Since rainforest bacteria and trees depend on each other for life, the

　　relationship they form is termed ______。

　　9. Plant species are dispersed over a large area with the help of ______。

　　10. As we are still ignorant of millions of unique life forms in the rainforest,

　　deforestation can be compared to the destruction of ______。