1.数值大与小的比较
在同时期比较两个事物的数值时，例如，表达A大B小，常常用表示对比的连词while将两句话连接起来，并且在while后面的B事物前加上much more或者much less一类的比较级，以突出B的小，跟A做对比。例如：
Lamb and chicken were eaten in similar quantities , while much less fish was consumed .
或者B事物前加用only来表示数值很小，又例如：
nuclear power,..., had developed into the main source, producing almost 75% of electricity, at 126 units, while coal and oil together produced only 50 units.
变化幅度的大小也能够被类似的句式表达，比如：
The consumption of fish also declined, but much less significantly to just below 50 grams,
2.增长与减少的比较
这也是段落内部十分常见的对比方式。先描述A下降或上升了，然后用while或者类似的连词连接后面的B上升或下降了;同时，这种比较也适用于段落之间，比如正文的一个主体段写A,B和C都上升了，下一个主体段写D下降了。需要注意的是，如果是段落间的比较，则不适合用while，而应该用In contrast, Conversely, on the other hand一类表示意群对比的句首词。例如：
The consumption of chicken, on the other hand, showed an upward trend,
段落内部的比较还是可以放心大胆的用while,例如：
However, while the figures for the Western countries grew to about 15% in around 1990, the figure for Japan dippedtoonly 2.5% for much of this period,.