As pilots get closer to the speed of sound:
O
A. there is not enough thrust to propel the airplane past the sound
waves.
O
B. the airplane becomes more difficult to fly because there is more
drag from air molecules.
O
C. the air molecules move out of the way more quickly, which creates
a sonic boom.
O
D. they notice that the airplane uses less fuel because the pull of
gravity decreases.

120,630,890

step-by-step explanation:

110+10=120,620+10=630,880+10=890

answer : one can design an experiment using a liquid and an additive that can be added to the liquid and observe the chemical changes in the reaction species.

one would need a beaker which is filled with a known amount of the liquid in which thermometer is placed to measure the temperature changes; after addition of the additive to the liquid solution one can note down the temperature change and find whether the reaction is endothermic or exothermic in nature. by subtracting the initial temperature value with the final temperature one can find the temperature changes.

various combinations of liquid and additive can be used. liquid in this case can be a known quantity of water and additives can be epsom salt or without epsom salt the experiment can be conducted to notice the changes. water and ice, hydrogen peroxide and dry yeast, vinegar and baking soda,etc.