请翻译以下两篇短文并指出翻译难点所在：
l. Technological development and the economic growth dependent on it have brought about great changes in the economic systems which were described by the classical economists. Production has been concentrated into a few large corporations, such as the oil companies and the automobile producers. At the same time, it has been the practice for large companies to buy whole or controlling interests in unrelated areas of production: aircraft companies which own radio and telev ...