精选优质文档-倾情为你奉上Lesson OneThe Development of RubberHere is a story about rubber.In the early part of the eighteen-hundreds, the Americans made use of natural for the first time. First they made overshoes to keep their feet dry. Then came a certain Mr. Mackintosh, who made coats of cloth covered with natural rubber. But these first rubber overshoes and raincoats were all soft and sticky in summer, and hard and unelastic in the winter when it was cold, the rubber we have today is not stic
