Majority of the students are the only child.
only child=独生子女. single child用词是错的, 在这里single child变成了"单身小孩"
我在国外混了8年了, 准没错
大多数学生都是独生子女
Most of the students are the only child in their family
Most students are single child.
Most of the students are only children.
Most students are only-children