keep one's finger on the pulse ofdrop from the clouds

If one keeps/has one's finger on someone's pulse, one is in a position to monitor the working (to some extent) of their heart. By extension, if one has one's finger on the pulse (of political activity, for example), one is in touch with what is going on.keep one's finger on the pulse of 本义是把脉(熟知/监控某人的健康状况), 引申为对周围进行/发生的事情很了解, 消息灵通.drop from the clouds没听说过.

谢谢．．．