twin brother

例句：

1. 1.They have a twin brother who is just as smart as they are.
   他们有一个和他们自己一样聪明的双胞胎兄弟。
2. 2. The twin brothers are very close and always support each other.
   这对双胞胎兄弟非常亲密，总是互相支持。
3. 3.The twin brothers were born on the same day, but their birthdays are only one month apart.
   这对双胞胎兄弟在同一天出生，但他们的生日只相差一个月。