Questions

A filament is a metal wire that glows when electricity is channeled into it. The filament of an electric bulb is made of Tunsten. 

Because of its high melting point and its greatest tensile strength, it makes for a good filament in light bulbs.

The plural form of ‘Poor’ is ‘Poor’. ‘Poors’ is incorrect. Also, according to the subject verb agreement, ‘interests’ is the correct form of verb.

Thus, the correct formation would be, ‘We are doing this in the interests of the poor’.

The Ozone layer which is present in the Earth's atmosphere protects it by restricting from UV or Ultraviolet radiation, the dangerous rays contained by Sun.

Blueberries are the saddest fruits.

Reason ::

In English some colors are associated with feelings. Blue is associated with sadness. When you "feel blue" it means that you are feeling sad.

Hence, as blueberries has blue in its name it indicates that that is the saddest fruit in logic.