Questions

Phoebus Levene was an organic chemist in the early 1900's. He is perhaps best known for his incorrect tetranucleotide hypothesis of DNA. He is who studied the structure and function of nucleic acids.

The discovery of Identification of Ribose and Deoxyribose is attributed to Phoebus Levene.

A Jig saw puzzle pieces are in different colors which have different shapes. 

You can put it anywhere you like but there is only one right place for it to be fit in it.

Investment and asset are really close in meaning. Investment is when you put your money in stock, bond or other financial instruments. Whereas Asset is what you own generally reffered to land, proprietorship , factory, etc.

Venus is known as earth's twin because of its closeness to the earth with respect to size, mass(weight) and density.

A locked file can be accessed by only one user.

A command economy types of government decide which goods would be produced without any interference of the public.

Command economy ran in Germany during the rule of Adolf Hitler. 

A command economy tends to exist under a socialist government that provides a lot of regulation.