The example in the river was to show how sound and light waves might
travel indicating how the doppler effect works. In real life, how does
doppler effect work? Check all boxes that show a situation which would
produce the doppler effect."
-the sound producer is stationary and the observer moves.
-the observer is stationary and the sound producer moves.
-both the observer and the sound producer can move towards or away from each
other
-the observer and the producer move in the same direction at the same speed
-neither observer or producer move, but the producer changes the frequency emitted.
-Other

high-sugar diet and high cholesterol

this is an example of "committed" time.

committed time, as contracted time, takes need over essential and available time since it is seen as profitable work. it alludes to the time allotted to keep up a home and family. at the point when a man is commuting using committed time this individual may feel that the drive is an obligation to family, for example, strolling youngsters to class or driving a mate to work. contracted and committed time clients may feel that their commute could really compare to the commute of important or leisure time clients on the grounds that their commute is profitable work. in this manner, they might be more disposed to pick a mechanized method of movement.  

in most common fires, oxygen is needed for an oxidation reaction to takes place. the combination of oxygen with any element as fuel can create fire and combustion will occur especially if wood, light materials and other combustible things are combine with oxygen.