Cardiovascular disease in smokers is primarily due to the in cigarette smoke. a. nicotine b. tar c. carbon monoxide d. both a and c

the sun d the answer is sun

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)]