錯例：Oneof the most challenging problem is who should be responsible for looking after the elderly people.
    正解：Oneof the most challenging problems is who should be responsible for looking after the elderly people.
    改錯練習：
    1. What our modernsociety values are the personality and creativity.
    2. Private car willexert adverse impacts on the environment and traffic of the whole society.
    3. Long-distance education provides students interesting way to learn.