填空题 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

填空题 Washoe could make signs to communicate ______

填空题 Some scientists doubted ______

填空题 Washoe taught three younger chimps sign language ______

填空题 The experimenters thought Washoe was intelligent ______