阅读下面短文, 在空白处填入1 个适当的单词或括号内单词的正确形式。Lions seem to use yawns (哈欠) to send【小题1】 (signal) to each other. The observation provides the first concrete evidence 【小题2】 yawning can synchronize (使同步) behavior in an animal species.
Elisabetta Palagi, from the University of Pisa in Italy, 【小题3】(intend) to study another animal. But when her students were collecting data in South Africa, they started sending 【小题4】(she) videos of lions as well. Watching the videos, Palagi couldn’t help but notice how the lions 【小题5】(keep) yawning one after another and then got up and moved in near synchrony.
She asked her students to focus on 19 lions 【小题6】(live) in two social groups. They took nearly 5 hours of video per lion over a four-month period. The team found that when 【小题7】single lion yawned and another lion could see it do so, the second lion started to yawn within 3 minutes of the first. The chance 【小题8】the second lion yawning within the 3-minute window was 139 times higher than it would have been if the first lion hadn’t yawned. The team also realized that the yawns led to actions, 【小题9】usually involved getting up and walking away. The lions were 11 times 【小题10】 (likely) to synchronize their next moves with the first lion following a spell of yawning.