do a bird count..
进行一次鸟类的清点
1. VOICE: How high1 can a bird count?
鸟儿能够数算数字吗?
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2. We do a bird count once a year to study changes in bird numbers.
我们每年数一次鸟儿,以研究鸟儿在数量方面的变化；
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3. A complete head count of every animal, insect and bird living at the zoo is to take place, with more than 650 different species to tally up.