讲解：
Attention, please!
注意:
Attention, please! Passengers for flight KL412 are requested to go to gate 21 immediately.
请注意！请 KL412 航班的乘客立即到 21 号门登机。

acknowledge sb / sth (as sth)
承认(权威、地位)
The country acknowledged his claim to the throne.
这个国家承认了他继承王位的权利。

introduce A (to B) | ~ A and B | ~ yourself (to sb)
把…介绍(给)；引见；(自我)介绍:
He introduced me to a Greek girl at the party.
他在聚会上介绍我认识了一位希腊姑娘。

token + sth
装样子的；装点门面的；敷衍的:
The government has only made a token gesture towards helping the unemployed.
政府只不过是做做样子表示了一下对失业者的帮助。

a top priority
优先事项；最重要的事；首要事情:
Education is a top priority.
教育是当务之急。