unit 1 to 6

unit one: check-up

1- Basics
2- Letters and numbers
3- Dates and times

unit two: Parts (1)

1- Naming 
2- Assembling
3- ordering

unit three: Parts (2)
1- Tools
2- Functions 
3- Locations

unit four: Movement 

1- Directions
2- Instructions 
3- Actions

unit five: Flow

1- Heating system
2- Electrical system
3- Cooling system

unit six: Materials

1- Material testing
2- Properties 
3- Buying