Give three reasons why leaves might turn red?

Douglas fir stops growing because it can't pull water any higher.

All tree leaves have 'thermostat' that maintains temperature.

Leaves shed new light on earlier arrival of spring.

Explanation:

answer : haversian

[explanation: -(compact bone is organized as parallel columns, known as haversian systems, which run lengthwise down the axis of long bones. these columns are composed of lamellae, concentric rings of bone, surrounding a central channel, or haversian canal, that contains the nerves, blood vessels, and lymphatic system of the bone)]