Luis is conducting an investigation to determine if modern horseshoe crabs evolved from extinct organisms call trilobites. Which of the following should Luis use to determine if there is
evidence to support his idea?
a. The fossil record of trilobites
b. The population size of trilobites
c. The traits of all extinct animals
d. The population size of horseshoe crabs

When molecules of water vapor in the air come in contact with a cold can of soft drink , they lose energy ,slow down,and form a liquid due to decrease in ?

Why is the bond angle in a water molecule less than the bond angle of methane? a. the central oxygen atom in water has two lone pairs of electrons, whereas the central carbon atom in methane has no lone pairs. b. the central hydrogen atom in water has one lone pair of electrons, whereas the central carbon atom in methane has two lone pairs. c. the central oxygen atom in water has four lone pairs of electrons, whereas the central carbon atom in methane has only one lone pair. d. the central oxygen atom exerts more repulsive force on surrounding atoms than the central carbon atom in methane does. reset next

Diffraction is when light is bent around obstructions. which of the these observation about clouds would indicate diffraction? a) after rain storms, you can sometimes see rainbows. b) clouds are white or gray and cannot be seen through. c) on a cloudy day, the temperature tends to be cooler than a sunny day. d) the edges of dark clouds appear lighter. this