Anyone wanna talk trying to calm my nerves please

How many questions do they give on the sat

The authors use the word “backbone” in lines 3 and 39 to indicate that

Luminous objects such as flashlights emit light that we can see. how do we see an object that isn’t luminous? a. the object emits light that reaches our eyes. b. light reflects off the object and reaches our eyes. c. light passes through the object uninterrupted. d. light is fully absorbed by the object. e. we can’t see an object that isn’t luminous.