30.Keen observers and quick learners，they are astute about the intentions of other creatures，including researchers，and adept at avoiding them.
(并列同位语keen observers and quick learners)
乌鸦是敏锐的观察家和快捷的学习者，它们对其他生物(包括研究人员)的意图感觉非常敏锐，并且善于躲开它们。
分句1. they are astute about the intentions of other creatures，including researchers
分句2. and adept at avoiding them.
1和2是并列
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