@CNN: Koko, the gorilla who mastered sign language, died this week in her sleep at age 46, The Gorilla Foundation says. She was said to have understood some 2,000 words of spoken English. https://t.co/9WEo5pbpqX https://t.co/cJJaBhKLCM

@CNN: Koko, the gorilla who mastered sign language, died this week in her sleep at age 46, The Gorilla Foundation says. She was said to have understood some 2,000 words of spoken English. https://t.co/9WEo5pbpqX https://t.co/cJJaBhKLCM