How many hydrogen atoms are present in each water molecule?
o a. 2
o b. 1
o 0.4
o d. 3

Answer is A.

Explanation:

H2O, meaning 2 hydrogen and 1 oxygen. This is the recipe for water basically.

a and c are the answeres

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)]