II. Read the passage carefully and then fill ONE suitable word in each gap.

Everyone knows that parrots can imitate human speech, but can these birds also understand the meaning? Two decades ago, researcher Irene Pepperberg started working with Alex, an African grey parrot, and ever since then, she has been building (76) ___ data on him. Pepperberg, whose recently published book The Alex Studies makes fascinating reading, claims Alex doesn't copy speech but intentionally uses words to get (77) ____ it is what he wants.

In actual (78) _____, some of his cognitive skills are identical to those of a five-year-old child. (79) _____ a child's, Alex's learning has been a steady progression. Early on, he (80) _____ vocalize whether two things were the same or different. Now, he carries out more complex tasks. Presented (81) _____ different-colored balls and blocks and asked the number of the red blocks, he'll answer correctly. He requests things as well. (82) _____ he asks to sit on your shoulder and you put him (83) _____ else, he'll complain: "Wanna go shoulder."

A few experts remain skeptical, seeing very (84) ____ in Alex's performance beyond learning by association, by means of intensive training. Yet Alex appears to have mastered simple two-way communication. As parrots live for 60 years or more, Alex may surprise (85) _____ all further.