Why do scientists need control groups?

The personal identification number that students need to apply for federal student aid

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.

Essay questions may also be referred to as a. talk questions c. hard questions b. explain questions d. think questions