Questions

• International Workers' Day, also known as Labour Day in some countries, is a celebration of labourers and the working classes that is promoted by the international labour movement, socialists, communists or anarchists. 
• It occurs every year on May Day which is May 1st. It is the day to pay tribute to the Labourers. Without them nothing will complete. 
• In India, the first Labour Day, or May Day, was celebrated in 1923 in Chennai.

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.

Nickel

Steel is not a compound or element. Steel is an alloy of iron and carbon and other elements and hence it is a mixture. Because of its high tensile strength and low cost, it is a major component used in buildings, infrastructure, tools, ships, automobiles, machines, appliances, and weapons.

United State Library of Congress, Washington D.C.

Warm, moist climate (with a temperature of 180 C- 270C and well-distributed rainfall between 125 to 200 cms) and deep, loamy, well-drained soil made of weathered lava are most suitable for the cultivation of coffee. However,  Brazil is a quantity producer and not a quality producer.