Now she must talk her sister through the process a step at a time.
现在她必须向她姐姐详细解释这个过程，一次只说一个步骤。
《柯林斯英汉双解大词典》
2
There, you may see a brother, a sister, a step-sibling, a twin.
那里你可能看到兄弟，或者姐妹，或者异父母同胞，或者双胞胎兄妹。
3
GAP Adventures took its focus on social and environmental responsibility one step further by launching a sister nonprofit organization, the Planeterra Foundation, in 2002.