A: Generally, streams are swift;
Spring water, as the Book of Songs said: Boiling threshold spring →bii 3 boo 3 gong 5 zuan 5 (Guangdong Heluo dialect pronunciation; Boiling → another pronunciation: pii poo rhymes with "bii boo" and "piipoo" in daily life.
Then, it is feasible to use "Ding Dong" to describe the singing in spring, and it is almost the same as the description in The Book of Songs.