twins

n.

孪生儿之一，双胞胎之一( twin的名词复数 )；两个相像[密切关联]的人[物]之一；双胎；

conjoined twins联胎；联体双胎；联体双生儿

fraternal twins异卵双生

siamese twins n. 暹罗双胎；连体婴

1. He is the elder of the twins.
   他是双胞胎中的哥哥。
2. The twins are unequal in height.
   这一对孪生儿高矮不一样。
3. The twins are so alike that no one can distinguish one from the other.
   这对孪生儿长得很像，无人能分辨出谁是谁。

Methodology for Genetic Studies of Twins and Families
Methodology for Genetic Studies of Twins and Families.
Gut microbiota from twins discordant for obesity modulate metabolism in mice
The response to long-term overfeeding in identical twins.
Twins and Intergrowth Defects in High-Tc Bi–Sr–Ca–Cu–O Superconductor Examined by High-Resolution Electron Microscopy
Perinatal outcome of singletons and twins after assisted conception: a systematic review of controlled studies
Genetic Susceptibility to Death from Coronary Heart Disease in a Study of Twins
Illict psychoactive substance use, heavy use, abuse, and dependence in a US population-based sample of male twins.
Genetic and environmental contributions to alcohol abuse and dependence in a population-based sample of male twins
The role of inheritance in sporadic Parkinson's disease: Evidence from a longitudinal study of dopaminergic function in twins