Answer:
Chitin
Explanation:
A fly's main body is made of a thorax and an abdomen. These parts are covered by a hard exoskeleton made of a bony substance called chitin.
I would say
change: Temp
Measure: Mass
Control: Volume
"n" represents principal energy level or principal quantum number. Principal energy levels are then subdivided into sublevels. The level of principal energy level is always equal to number of sublevels. Therefore if <span>principal energy level</span> = 4, then there are also 4 sublevels present, namely: 4s, 4p, 4d and 4f sublevels.
D, litmus paper indicator
