After reading the paragraph, circle the letter of the sentence that best expresses the implied main idea. One factor that kept FM radio from developing as much as AM was that more people had AM receivers than FM receivers, and it was not possible to pick up FM on a standard AM radio. Many owners of AM stations also owned FM stations. Several factors held back FM radio's development. By moving FM to a different broadcast spectrum, the FCC made all existing FM radios useless.
Orangutans are intelligent apes that live in the forest of the Asian islands of Sumatra and Borneo.
Because of a growing human population, those forests are being cut down for lumber and to create farmland. The less forest there is, the fewer the orangutans that can be supported. To add to the problem, orangutans reproduce very slowly. On average, females have just two or three babies over their lifetimes. Today, there are only two thousand orangutans in Borneo and even fewer in Sumatra.