3、Put the correct words into the blanks in the following passages （直接作答，不要手写拍照） An elastomer (or rubber) ______ a polymer having relatively weak interchain forces and high molecular weights. When the molecular chains are ‘straightened out’ or stretched by a process of ______ , they do not have sufficient attraction for each other to ______ the oriented state and will retract once the force is released. This is the basis of ______ .However, if the ______ are very great, a polymer will make a good fiber. Therefore, when the polymer is highly stretched, the ______ chain will come under the influence of the powerful attractive forces and will “crystallize” permanently in a more or less oriented matrix. These ______ will then act virtually as crosslinks, ______ in a material of high tensile strength and high initial modulus, i.e., a fiber. ______ , a potential fiber polymer will not become a fiber unless subjected to a 'drawing' process, i.e., a process resulting in a high degree of ______ orientation.