The class is less than thirty in number, which is easer for teachers to conduct class activities.The class have disagreed among themselves about where they should go and have picnic.

• 当名词词组中心词为表示度量、距离、金额、时间、书名时，往往可以根据意义一致的原则，把这些复数名词看作一个整体，谓语动词用单数形式。