usefulness
/ˈjuːsflnəs/📚 10136 61GREthe quality or fact of being useful. "faults that affect the book's usefulness"
noun [具体名词]有用；有效性；有益
There are doubts about the usefulness of these tests.
这些试验是否有用，人们有所保留。
单词造句:
There are doubts about the usefulness of these tests.
这些试验是否有用，人们有所保留。