Questions

A colon is used to connect two sentences when the second sentence expands, illustrates, explains, summarizes, or sharpens the first. Both sentences should be complete, and their content should be very closely related.

Example:

This girl has two favorite hobbies: watching movies and seeing how long she can hold her breathe.

Its FRIDAY.

The alphabet 'Y' resembles same as the questioning word WHY in sounding.

Hence,  alphabet Y is a question.

Benchmarking is the process of comparing one's business proceses and performance metrics to industry bests or best practices from other industries. Dimensions typically measured are quality, time and cost.

Marginal propensity to consume (MPC) in economics is a metric that quantifies induced consumption, the concept that the increase in personal consumer spending (consumption) occurs with an increase in disposable income (income after taxes and transfers).

The purines are bases in the DNA. The two purines in DNA are Adenine and Guanine. These two purines forms hydrogen bonds with their complimentary pyrimidines such as Thymine and Cytosine to keep the two rails of the DNA molecule together.