Answer:
d
Explanation:
A number of human activities can impact on the water cycle: damming rivers for hydroelectricity, using water for farming, deforestation and the burning of fossil fuels.
Answer:
333.3 m
Explanation:
Given

Potential energy =
......Equation(1)
We know that
Potential energy=mgh
Kinetic energy =
Now From the Equation(1)

Answer:
D. crystalline solid that conducts current under certain conditions
Explanation:
Semiconductors are crystalline solids that has the ability to conduct electrical currents but on certain conditions e.g heat. The conduction of semiconductors is less than that of conductors (metals) but more than insulators (nonmetals), hence, they are said to be intermediates of conductors and insulators in terms of electrical conductivity.
Examples of semiconductors are silicon, boron, carbon, germanium, arsenic etc.
perimeter of a rectangle = 2(L+B)
90=2(L+B)
90/2=L+B
45=L+B