How does apricot flower tell frog that spring is coming?

Good children are cheated by the Chinese teacher. What a stupid question. It was the temperature that awakened the frog. Frogs are sleeping soundly and can't hear what they can't see. How does apricot flower "call"? Calling is futile. It is better to let the children personify the awakened frog, look at the apricot flowers that are also awakened by the warm spring sun, and talk about spring together.