Questions

The ball with which Table Tennis is played is called Ping Pong Ball.

According to the International rules, the diameter of the ping pong ball must be not less than 39.5 millimeters and not greater than 40.5  millimeters having a mass of 2.7 grams.

Helioseismology is the study of the solar interior using observations of waves on the Sun's surface. It has done much to improve our understanding of the interior of the Sun, testing the physical inputs used to model stellar interiors and providing a detailed map of the Sun's structure and internal rotation.

Overhead costs should be figured into the cost estimate. Desired profit considered together with other factors such as market demand, availability of resources, prior experience are then used to determine the optimal price.

The words do, does and did often cause confusion in the English language. They are all forms of the verb to do.

It is also common to use do, does and did as auxiliary verbs (or helping verbs) together with another verb in its base form. This is used to create negative sentences, questions, or for adding emphasis.

Examples :: 

* Russel did a great job on his debut match for team.

* Did you catch the train this morning?

* When did they arrive home?