Questions

Seawater or salt water is water from a sea or ocean.

On average, seawater in the world's oceans has a salinity of approximately 3.5% or 35 parts per thousand. This means that for every 1 litre (1000 mL) of seawater there are 35 grams of salts dissolved in it.

Hence, The average salinity of seawater is 3.5%.

It refers to the possibility for an investor to experience  losses due to  factors that affect the overall performance of the financial markets. Market risk cannot be eliminated through diversification, though it can be hedged against. The sources of market risk include natural disasters, recessions, political turmoil, changes in interest rates and terrorist attacks.

Dipsomania is one word substitute for Irresistible craving for alcoholic drinks.

Expedite means making an action fast or sooner i.e, to accomplish a work as quickly as possible.

Hence, halt means stop and it is opposite of Expedite.

Metropolis is a central city with the developed area surrounding it while Megalopolis is a region made up of 2 or more metropolitan areas.