四级语法：谓语动词用复数的情况

       1) both, some, few, many等用作主语或修饰主语时，谓语动词用复数。
        【例如】
        Both of my parents are over seventy years old.
        Many students in my class have creative thoughts and wide knowledge.
        2)“the +形容词”作主语，在表示一类人或事物时，谓语动词用复数。
        【例如】
        The aged are well taken care of by the government.
        The poor are often looked down upon by the rich.
        The young have respect for the old in China.
        3) a number of, a lot of, any of, most of, the rest of, some of, none of, all of修饰复数名词时，谓语动词用复数。
        【例如】
        Most of the teachers are responsible and knowledgeable.
        A number of books have been published on the subject.
        None of the books attract me a lot. the number of表示“……的数量”，谓语动词用单数。
        【例如】
        The number of books published on this subject is simply amazing.
        The number of foreign visitors to China has been increasing over the last several years.
        4)集合名词作主语时，当名词表示整体时，谓语动词用单数；当名词强调集体中的个体时，谓语动词用复数。
        【例如】
        The family is the basic unit of society. The family have agreed among themselves to spend their vocation in Europe.