Answer:
D. Sand carried by rivers flows over and weathers the rocks.
Explanation:
The sand in the river is move because of the flow of the river and as the sand moves it grinds on the rocks in the river. This starts a process know as abrasion, in other words it means that it wheathers(grinds) against the rocks.
Answer:

Explanation:
Given:
The area of the house 
The height of the house 
We need to find the volume of a typical house.
Solution:
We find the volume of the house by multiplying the area of the house and height of the house.


Area and height of the house are known, so we substitute these value in above equation.


Now we convert the unit from feet to meter.
Divide the volume by 3.2808 for 


Therefore, the volume of the house is 
Answer: the first law of thermodynamics
Explanation:
There are various properties which are exhibited by substances like physical properties,chemical properties,magnetic properties,electric properties etc.
By simply observing the substance we can not get any idea about the property of a substance.One has to conduct various tests in order to reach at his or her conclusion. The scientific tests provides a better understanding about the nature of substance and the changes that happen under various conditions and parameter.
Answer:
Explanation:
Wgen the sound is emitting from two speakers, the sound waves interfere each other. the locations at which the destructive interference occurs, we get no sound and the locations where constructive interference occurs, the sound occurs at that locations.