Correct Answer :   Emigration

Correct Answer :   Volcano

Volcanoes are known as the safety valves of nature because they periodically release the pressure that builds up because of tectonic activity in the Earth's crust and even lower layers.

Correct Answer :   Coal, Natural Gas and Petroleum

Traditional thermal power plants: also called combustion power plants, they operate with energy produced by a steam boiler fueled by coal, natural gas, heating oil, as well as by biomass. The steam activates a turbine which, in turn, drives an alternator to produce electricity.

Correct Answer :   Salt Water

Halophytes are salt-tolerant plants that grow in waters with high salinity, such as in mangrove swamps, marshes, seashores and saline semi-deserts. Only two per cent of the plant species found on the Earth are halophytes.

Correct Answer :   describing their qualifications

Correct Answer :   Geothermal Energy

Correct Answer :   0­-4%

Water vapor concentration varies from trace amounts in Polar Regions to nearly 4 percent in the tropics. Most prevalent gases are nitrogen (78 percent) and oxygen (21 percent), with the remaining 1- percent consisting of argon, (. 9 percent) and traces of hydrogen ozone ( a form of oxygen), and other constituents.

Correct Answer :   Ozone Depletion

Correct Answer :   Electrical Resistance

Ohmmeter, instrument for measuring electrical resistance, which is expressed in ohms. In the simplest ohmmeters, the resistance to be measured may be connected to the instrument in parallel or in series. If in parallel (parallel ohmmeter), the instrument will draw more current as resistance increases.

Correct Answer :   Alkaline

The pH scale ranges from 0 to 14, with 7 being neutral. pHs less than 7 are acidic while pHs greater than 7 are alkaline (basic).