383. Other animals, it is true, communicate with one another by means of cries: for example, many birds utter warning calls at the approach of danger; monkeys utter different cries, such as expressions of anger, fear and pleasure.
譯文
其他動物通過叫喊聲相互溝通，這確有其事：例如，許多鳥在危險臨近時發(fā)出警告的叫聲；猴子發(fā)出不同的叫喊聲來表示憤怒、恐懼和高興。
點睛
it is true為插入語。
communicate with意為“與……溝通，交流情況”。如：
The police communicate with each other by radio. 警察通過無線電相互聯(lián)絡(luò)。
by means of意為“以……方式，通過……的手段”。如：
The theory is illustrated by means of Power Point. 該理論以PPT的形式進行講解。
utter此處意為“發(fā)出（聲音）”。如：
Why do you utter a sign? 你為什么要發(fā)出嘆氣聲呢？
at the approach of意為“在……將到的時候”。如：
A bird has to give way at the approach of an elephant. 大象走過來，小鳥要讓路。
