The successive stages of pronunciation for the Old English twā would thus be /twɑː/, /twɔː/, /twoː/, /twuː/, and finally /tuː/. In mathematics
Two is the smallest prime number, and the only even prime number, and for this reason it is sometimes called "the oddest prime". As the smallest prime number, it is also the smallest non-zero pronic number, and the only pronic prime. The next prime is three, which makes two and three the only two consecutive prime numbers. Two is the first prime number that does not have a proper twin prime with a difference two, while three is the first such prime number to have a twin prime. In consequence, the first pair of twin primes, three and five, encase four in-between, which is the square of two, or 
  
    
      
        
          2
          
            2
          
        
      
    
    {\displaystyle 2^{2}}
  . Two is the first Sophie Germain prime, the first factorial prime, the first Lucas prime, and the first Ramanujan prime.
Linear and whorled nevoid hypermelanosis (also known as "Linear nevoid hyperpigmentation," "Progressive cribriform and zosteriform hyperpigmentation," "Reticulate and zosteriform hyperpigmentation," "Reticulate hyperpigmentation of Iijima and Naito and Uyeno," "Zebra-like hyperpigmentation in whorls and streaks," and "Zebra-line hyperpigmentation") is a disorder of pigmentation that develops within a few weeks of birth and progresses for one to two years before stabilizing. : 549   There is linear and whorled hyperpigmentation following the lines of Blaschko without preceding bullae or verrucous lesions. : 549   It is important to exclude other pigmentary disorders following the Blaschko lines before making a diagnosis of linear and whorled nevoid hypermelanosis. The differential diagnoses include incontinentia pigmenti, linear epidermal nevus, hypomelanosis of Ito and Goltz syndrome. Recently, a case of linear and whorled nevoid hypermelanosis was reported in a Malaysian Chinese girl. See also
Skin lesion
List of cutaneous conditions

References


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