Which are characteristics of a ray when it hits a boundary and refracts, but not when it hits the boundary and reflects? check all that apply.

a. changes direction
b. changes speed
c. does not change direction
d. does not change speed
e. bounces off the boundary
f. passes through the boundary

1. when conducting a test on what kind of music increases the growth of plants, all of the following would fail to meet to fair test standard except (1 point) using different kinds of plants. giving some plants more water than others. exposing the plants to different types of music. using nutrient-rich soil for one and lesser soil for others. 2. engineering uses scientific thinking to solve real-world problems. (1 point) true false 3. what does it mean to test a hypothesis? (1 point) pass a quiz on other scientists’ results analyze only the results from scientific sources not make assumptions about how an experiment will turn out see if the results of an experiment are what the scientist predicted