When there are many flowers, I know that when the rain falls, there will be less rain. A five-character Tang poem

Select five of the characters (because it is a five-character Tang poem):

Flowers, many, knowledge, few, fall. The poem consists of:

How many flowers have fallen?

This is a poem from "Spring Dawn" by Tang Dynasty poet Meng Haoran. The full poem is as follows:

Spring Dawn

Meng Haoran

Spring sleeps unconsciously At dawn, I hear birds singing everywhere.

The sound of wind and rain at night makes one know how many flowers have fallen.