Which two body systems work together closely to produce movement in human limbs

Can I have a sentence for impediment

When is a zero not significant?

It would take one light year to travel to the sun. True False

One of the purposes of an experiment is to determine whether the dependent variable affects the independent variable. T or F?

Why does green light has a lower frequency than blue color?

How many layers of material were the roads made of? a. two c. four b. three d. five

Red light has a shorter wavelength than yellow light.

Approximately what is the parallax angle of a star that is 20 light-years away?

If the Earth and distant stars were stationary (motionless) in space, what would we observe about the wavelength from these stars? A. Wavelengths measured would match the actual wavelengths emitted. B.

Two fire trucks with sirens speeds towards and away from an observer. Which statement is true involving the Doppler effect observed by the observer?