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 blood types in the US are O positive and A positive.
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.
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.
rudder rudder post
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.
You have been asked by your manager to conduct a preliminary search of recommending the two most common types of contemporary planning techniques - Project Management and Scenario Planning.
internal and external
The two types of radioactive dating that are most common are: Carbon 14 and Potassium-Argon. There are quite a few others.
Third is the most common, followed by first.