People get natural rubber from rubber trees / as a white, milky liquid，which is called latex. / They mix it with acid, and dry it, / and then they send it to countries all over the world. / They started rubber plantations in countries / with hot, wet weather conditions, / but these still could not give enough raw rubber / to meet the needs of growing industry. / It was always possible that wars or shipping trouble could stop supplies. / In the end, they found a way of making artificial, man-made rubber / which is in many ways better than / and in some ways not as good as natural rubber. / It is usually cheaper than natural rubber. / Today, the world needs so much rubber that / we use both natural and artificial rubber in large amounts. /