Questions

The inside of the bulb being a vacuum, the outside air rushes in when the bulb is broken. The vibrations of the rushing air molecules produce the sound.

A Dome-shaped, muscular and membranous structure that separates as a partition of the thoracic and abdominal cavities is Diaphragm. 

Thoracic or chest cavity ::  It is the cavity where the heart and lungs are present. It is the second largest hallow space in the body.It also has vertebral column, ribs, breast bone,...

Abdominal cavity :: It is the cavity where the digestive tract, liver, kidneys, the spleen, pancreas,... are located. It is the largest hallow space of the body.

Using automatically incrementing IDENTITY columns is very popular with database developers. You don’t need to explicitly calculate unique surrogate keys when inserting new data, the IDENTITY column functionality does that for you. The IDENTITY feature also allows you to specify useful Seed and Increment properties. When you use an INSERT statement to insert data into a table with an IDENTITY column defined, SQL Server will generate a new IDENTITY value.

You can use the @@IDENTITY variable and the SCOPE_IDENTITY and IDENT_CURRENT functions to return the last IDENTITY value that has been generated by SQL Server. This is very useful when you need to return the key for the row that has just been inserted, back to the caller.