this
this is没有缩写形式。this is的意思是这是。this is的例句：I think they got the message that this is wrong（我认为他们已经得到了消息，知道这是错误的）。
this is的例句：This is a clear demonstration of how technology has changed（这清楚地表明了技术已有了怎样的进步）；This is positively the last chance for the industry to establish such a system（这绝对是该产业建立这样一个体系的最后机会了）。
