Questions

A number of possible explanations for why manhole covers are round include :

1. A round manhole cover cannot fall through its circular opening, whereas a square, rectangular, or oval manhole cover could fall in if it were inserted diagonally in the hole.

2. Circular covers don’t need to be rotated or precisely aligned when placing them on the opening.

3. A round manhole cover is easily moved and rolled.

4. Human beings have a roughly circular cross-section.

5. Round tubes are the strongest shape against the compression of the earth around them, so the cover of the tube would naturally be round as well.

6. It’s easier to dig a circular hole.

Tuberculosis (TB) was the leading cause of death in the United States and one of the most feared diseases in the world during the 19th and early 20th centuries.

Formerly known as Consumption diseases because many types of lung diseases were lumped under the term 'consumption'. Lung cancer and bronchitis were examples.

A : B = (800 × 8+ 900+ 1000+ 1100+ 1200): (1600 × 8+ 1700+ 1800+ 1900+ 2000)
A : B = 53 : 101
Profit of A ⇒ 7700 ×53/154 = 2650 Rs.

Magma is injected into surrounding rock forming an igneous intrusive.

Actually it is a plutonic formation in which magma present beneath Earth surface deforms the shape of rocks present above it
 

In the OSI model of computer networking, a frame is the protocol data unit at the data link layer. Frames are the result of the final layer of encapsulation before the data is transmitted over the physical layer.

A single packet on a data link is known as Frame.

Can’t delete a row from primary table if there are related rows in secondary table.