Complete the following statements with proper words or expressio

Complete the following statements with proper words or expressions according to the course book.If one wants to know whether a pair or mathematics takes a singular or plural verb, a ( ) dictionary is likely to supply the best answer.
【正确答案】：USAGE
【题目解析】：本题考查词典的选择。如果你想知道“a pair”和“mathematics”作主语时，它的谓语是用动词的单数形式还是复数形式，用法词典可能会提供最好的答案。