These pipettes differ by dimensions: volume, length, diameter, etc.
Political and physical maps
networked and hierarchical
There are a variety of types of fossils. These include cast fossils, mold fossils, petrified wood, as well as fossil fuels.
There are two main/most common, types of magnet. One is permanent and the other is temporary. There could be more detailed classifications, but I do not know them ;)
Eggs and sperm
The two most common types of compressors are the positive-displacement and the velocity or dynamic.
The two types of law are common and statutory.
The two most common blood types in the US are O positive and A positive.
The two types of law are common and statutory.
The two most common triads are the Major and the minor triad. The other two types of triads are diminished and augmented triads.
Common and Prefered
amoeba and paramecium are two common types of protozoan
Two types of nouns are common and proper nouns.
Netgear and trendnet
rudder rudder post
charcoal & petrol
twin and adoptee