How much of the world’s diversity is threatened as tropical forests are converted to agricultural use?
20 percent
30 percent
40 percent
50 percent

i do not know and i have a 100 in this class

your answer is "the 1950's"

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)]

a=c and then d= c because of the band so you get ac/dc and you add them together you get sound waves