phr. at the tips of sb.'s fingers 就在某人手头的，某人随时可用的
on (或 at) the tip of sb.'s tongue 就在某人嘴边的，某人差一点说出口的；某人差一点就能想起的
It was on the tip of her tongue to ask. 她差一点要开口问了。
I have his name on the tip of my tongue. 他的名字就在我嘴边。(意指一时想不起)
the tip of the iceberg (事物的)表面小部分；端倪
The plane crash is seen as merely the tip of an iceberg. 这次客机坠毁事件看来仅仅是事情刚露头。
to the tips of one's fingers 彻底地，完全地