Which of the following is a compound machine

knife

ramp

bicycle

screw

i would think klcio3

d.7.5cm is your answer

a longitudinal wave moves energy that is to the direction of the wave’s movement. - true

there is no correct list among the choices you've provided.

the list might look something like this:

-- baby human

-- piccolo

-- flute

-- soprano singer

-- trumpet

-- tenor singer

-- trombone

-- baritone singer

-- baritone horn

-- bass singer

-- tuba

since i had to make up the list myself, i made it easy on myself, and i didn't try to shuffle the string instruments and woodwinds into it too.