A pair of scissors .....................................
Interstellar gas clouds are common in many galaxy, like the Orion nebulae which many young stars are being born. A typical nebula is many light years in diameter and contains enough material mass to make several thousand stars the size of our sun. The majority of the gas in nebulae consist of molecules of hydrogen and helium-but most nebulae also contain atoms of other elements. All known element in our periodic table is also being made inside this crucible of this immense hot gas. The source of the organic molecules is still a mystery. Irregularities in the density of the gas causes a net gravitational force that pull the gas molecules close together.
True if you actually did it. false if you didn't
The frequency of the human ear canal is 2.92 kHz.
Explanation:
As the ear canal is like a tube with open at one end, the wavelength of sound passing through this tube will propagate 4 times its length of the tube. So wavelength of the sound wave will be equal to four times the length of the tube. Then the frequency can be easily determined by finding the ratio of velocity of sound to wavelength. As the velocity of sound is given as 339 m/s, then the wavelength of the sound wave propagating through the ear canal is
Wavelength=4*Length of the ear canal
As length of the ear canal is given as 2.9 cm, it should be converted into meter as follows:

Then the frequency is determined as
f=c/λ=339/0.116=2922 Hz=2.92 kHz.
So, the frequency of the human ear canal is 2.92 kHz.