Questions

The land breeze is a coastal breeze at night blowing from the land to the ocean. It is caused by the difference in the rates of cooling of the land and of the ocean. Once again, the bigger the difference in temperature between the two, the stronger the wind.

Electrostatic precipitator is used to control Air pollution. An electrostatic precipitator is a filtration device that removes fine particles, like dust and smoke, from a flowing gas using the force of an induced electrostatic charge minimally impeding the flow of gases through the unit.

Sad means being unhappy, sorrowful, mournful, wistful,...

Hence, Somber means cheerless i.e, unhappy which is synonym of sad. All other options are opposites of Sad.