1. Define Primary Key. Why do we need primary key ? 2. Define Field size.

3. Define Validation Rule.

4. . Not leaving the house and a lack of exercise can cause health problems like obesity. TRUE OR FALSE

5. Rebecca only works 3 days in a week but she works longer hours each day to ensure she hits the 40-hour work week.
-art-time working
-Compressed hours
-Job sharing
-Flexible hour

1 .The main purpose of primary key is to identify the uniqueness of a row, where as unique key is to prevent the duplicates, following are the main difference between primary key and unique key.

Explanation:

2. Field size means the dimensions along the major axes of an area in a plane perpendicular to the central axis of the useful beam of incident radiation at the normal treatment distance and defined by the intersection of the major axes and the 50 percent isodose line.

if you go to ask a question say ask, there should be something that looks like this. a camera lens.