1. Much of the evidence for the evolution of lifeforms on Earth has been obtained by
1. studying the life spans of present-day animals
2. correlating widespread igneous ash deposits
3. radioactive dating of metamorphic rock
4. examining fossils preserved in the rock Record

Since the pully is a simple machine so the mechanical advantage is a 1

Cardiac muscle causes movement in the bone.

The answer is b. all other properties are crucial.

Jenny and fred both play a long note on their trombones. a stationary observer hears the sound increasing and decreasing repeatedly in loudness. which of these must be true? the sound waves from the two trombones have slightly different frequencies.the sound waves from the two trombones have the same frequency.the sound waves from the two trombones have slightly different amplitudes.the sound waves from the two trombones have the same wavelength.the sound waves from the two trombones have slightly different velocities.  lolthe answer is          the sound waves from the two trombones have slightly different frequencies.