Questions

Alcohol is a drug.

Here in the given options, The girl, whom you have met yesterday is my sister is the sentence which has relative pronoun.

The pronoun which is used to connect a clause or phrase to a noun or pronoun is called as relative pronoun.

The most common relative pronouns are who, whom, whose, which, and that. Sometimes when and where can also be used as relative pronouns.

As water is cooled from 4 deg C to 0 deg C, the water reaches its freezing point and starts forming ice crystals. Then the volume of that ice cubes increases and its density decreases. Hence, it is the reason that ice will float on water as ice has less density than the water.

The defining right of a representative democracy is the ability to vote for representatives to make decisions on their behalf.

In democratic government, elections are held regularly, in which voters vote for someone who will serve in the levels of local, state, and federal government.

The main difference lies in the motive of the two parties. The main motive of the hedger is to hedge(minimize) the risk from the occurence of some events. 

The motive of the speculator is to gamble in the market in order to make the profit by buying/selling the derivative products.

Thailand

Developing a habit of wearing your lifejacket or PFD at all times also reduces the chance that you will drown should you find yourself in the water unexpectedly.

The world's largest car park can hold 20,000 vehicles and is situated at the West Edmonton Mall in Edmonton, Alberta, Canada. There are overflow facilities on an adjoining car park for 10,000 more vehicles.