Questions

A worksheet or sheet is a collection of cells in a file created with an electronic spreadsheet program such as Microsoft Excel or Google Sheets where we can keep and save data.

Here in a worksheet, we can select a single row or column or multiple rows or columns or we can select the entire worksheet. We can create multiple worksheets in a workbook.

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.