1、signal

(以手势、声音、行动等发出的)信号，暗号

They fired three distress signals.

他们发射了3次求救信号。

As soon as it was dark, Mrs Evans gave the signal.

天一黑，埃文斯夫人就发出了信号。

(用手势、声音等)发信号，发暗号，示意

The United manager was to be seen frantically signalling to McClair.

一会儿可以看到曼联主教练拼命地朝麦克莱尔示意。

He stood up, signalling to the officer that he had finished with his client.

他站起身，向警察示意他和他的当事人已经谈完了。

迹象;信号;预示

Kurdish leaders saw the visit as an important signal of support.

库尔德领导人将这次访问视作一种表示支持的重要信号。

The first warning signals came in March.

第一次警示出现在3月份。

2、call on

要求;呼吁;号召

One of Kenya's leading churchmen has called on the government to resign.

肯尼亚一位高级宗教人士要求政府下台。

Frequently he was called upon to resolve conflicts.

不断有人要求他出面解决冲突。

(短暂)拜访,探访，看望

Sofia was intending to call on Miss Kitts.

索菲娅打算去拜访基茨小姐。