What is required for a sound wave to be reflected? A. A sound wave with frequency equal to the natural frequency of the object
B. An obstacle for the wave to bend around
C. A hard surface for the wave to bounce off
D. A change in frequency as the wave enters another medium

Answer is in the photo. I can't attach it here, but I uploaded it to a file hosting. link below! Good Luck!

tinyurl.com/wpazsebu

because u need two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei to form isotopes.

so since they all have the same shape? i mean maybe because m& m and reeses are both chocolates

while cooking a piece of 1/2 pound beef steak, a cast iron pan (2.4kg in weight) was heated 260 celsius.