题目内容：
根据以下材料，回答题Washoe Learned American Sign Language
(1) An animal that influenced scientific thought has died. A chimpanzee named Washoe and born in Africa died of natural causes late last month at the age of 42 at a research center in the American state of Washington. Washoe had become known in the scientific community and around the world for her ability to use American Sign Language. She was said to be the first non-human to learn a human language. Her skills also led to debate3 about primates and their ability to understand language.
(2) Research scientists Allen and Beatrix Gardner began teaching Washoe sign language in 1966.In 1969, the Gardners described Washoe's progress in a scientific report. The people who experimented with Washoe said she grew to understand4 about 250 words. For example,Washoe made signs to communicate when it was time to eat. She could request foods like apples and bananas. She also asked questions like, "Who is coming to play?" Once the news about Washoe spread, many language scientists began studies of their own6 into this new and exciting area of research. The whole direction of primate research changed.
(3) However, critics argued Washoe only learned to repeat sign language movements from watching her teachers. They said she had never developed true language skills. Even now there are some researchers who suggest that primates learn sign language only by memory,and perform the signs only for prizes. Yet Washoe's keepers disagree. Roger Fouts is a former student of the Gardners. He took Washoe to a research center in Ellensburg, Washington.There, Washoe taught sign language to three younger chimpanzees, which are still alive.
(4)Scientists like private researcher Jane Goodall believe Washoe provided new information about the mental workings of chimpanzees. Today, there are not as many scientists studying language skills with chimps. Part of the reason is that this kind of research takes a very long time.
(5) Debate continues about chimps' understanding of human communication. Yet, one thing is sure--Washoe changed popular ideas about the possibilities of animal intelligence.
Paragraph 1 __________ A．if the Gardeners'argument was sound
B．because she was cleverer than other chimps
C．when she wanted to eat
D．while she was at a research center in Ellensburg
E．because she could use sign language to ask for fruits
F．while Washoe was learning sign language
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