英语指代

题目

英语指代
If its message were confined merely to information—and that in itself would be difficult if not impossible to achieve,for even a detail such as the choice of the colour of a shirt is subtly persuasive-advertising would be so boring that no one would pay any attention.请问此句中的that指代什么?为什么?

答案

that 指代的是破折号前面的内容,即：（传递的）的消息仅仅局限于信息.破折号之后想说,这种情况就算不是不可能,但其本身是很困难的.
读句子的时候,先不看破折号的内容,你这句后半个破折号过短了.应该是if its message were confined merely to information, advertising would be so boring that... 如果（广告中的）消息仅仅局限于信息的话,那么广告就变得如此乏味,以至于…….而那种局限本身,从现实上来看,即便不是不可能,也是很难做到的.