stay on top of
US /steɪ ɑn tɑp ʌv/
UK /steɪ ɑn tɑp ʌv/

1.
了解, 掌握
to remain informed about something; to keep up to date with something
:
•
It's important to stay on top of current events.
及時了解時事很重要。
•
She always tries to stay on top of her emails.
她總是努力處理好她的電子郵件。