Edwin Hubble used the Doppler effect to determine that the universe is expanding. After years of scientific research and observation of different celestial bodies through a telescope, Hubble found that the light from distant galaxies was shifted towards the red end of the spectrum. This red shift indicates that stars are moving away from us and from each other. This phenomenon is called the 'expansion of the universe', also known as the big band theory.
        
             
        
        
        
Answer:
Due to increment in food chains.
Explanation:
Biodiversity is actually the measure of changes in the ecosystem, genetic levels and various species levels. The sea otters introduced in California over last fifty years, increased the diversity in the ecosystem as well as in species too, thus changing the biodiversity. This was the impact of increase in food web in that particular area, the number of consumers, producers and prey increased thus increasing the biodiversity.
 
        
             
        
        
        
Answer:
After constructing a prototype of the device, the student concludes that in many regions the monetary cost of building and installing the  device would be higher than the cost of acquiring water from other sources. Which of the following would be most appropriate for the  student to do next?
redesign the device without the solar panel so that it plugs into an electrical outlet
Explanation:
Because of cost implication, the device is redesigned in order to use other source rather than water which would be cost-effective and generally accepted for use.
 
        
                    
             
        
        
        
Answer:
The correct representation is attached with the explanation.
Explanation:
In this representation of the surface tension, blue arrows between green water molecules are the possible molecules that can be used as the location for forming hydrogen bonds by a single molecule. Surface tension is the tendency of a liquid surface strectch to neighbouring molecules or ability to shrink in minimum surface area possible. Hydrogen bonds is an intermolecular force or interaction responsible for the surface are of liquide molecules. This bonds is towards every direction where the similar molecule present.