The 2 types most commonly used are
Cross brace (where poles are joined together to create a structure which is configured around the building)
Tower section. Interlocking gate sections used to make a square shaped tower
there are two types of scaffolding 1. coupler joint system 2. cup joint system
The two most common types of compressors are the positive-displacement and the velocity or dynamic.
The two most common triads are the Major and the minor triad. The other two types of triads are diminished and augmented triads.
The two most common types of the disease are Bancroftian and Malayan filariasis, both forms of lymphatic filariasis.
anticlines and synclines
O+ and A+
anticlines and synclines
rudder rudder post
The two most common types of trencher machines are the walk behind and the attachment models. They are used for digging trenches for laying pipe, cable or for trench warfare.
The two most common types of fans and blowers are the axial and the centrifugal, which together account for about 45 percent of the industry's output.
The use of long lines and different types of netsare the two most common methods of commercial fishing.
internal and external