1.主+谓
此结构是描写数据动态变化的首选句型结构，需注意的是主语必须是“数据”比如number, figure, percentage等，不能是其他名词，而谓语动词也只能是不及物动词比如increase, drop等。下面我们来看几个例子：
I.The number of visitors increased sharply between 1995 and 2005 inChina.
II.The percentage of people aged 15-46 dropped slightly by 10% during the 40 years.
III.The figure for college C rose gradually to 30,000 in2002.
IV.The number of aged people over 65 dropped slightly from 1960-1980.
V.The number of aged people over 65 fluctuated between 1 million and 1.2 million from 1940-1950.
2.主+谓+宾
此句型结构的特点在于谓语动词必须是及物动词，比如witness, see等，宾语位置要用表示动态变化的名词比如growth, reduction等，在主语位置上可以仍旧为数据，也可以是地点或者时间段。它对于用主谓结构表达的句子可以作同义转换，比如：
I.The number of visitors saw a sharp increase between 1995 and 2005 inChina.
II.China witnessed a sharp increase in the number of visitors between 1995 and 2005.
III.The years between 1995 and 2005 saw a sharp increase in the number of visitors in China.
