Which facts about the world’s rain forests are true?



Choose all answers that are correct.





A) Less than 1 percent of the plants in the rain forests have been tested for medicinal purposes.



B) Half of the known plant varieties in the world are found in rain forests.


C) Every continent except Antarctica has a rain forest.

D) The proportion of Earth’s landmass covered in rain forests has decreased by 50 percent since 1950.