求翻译：◇西部大开发政策：在新一轮西部大开发中，国家总投资将达3万亿元。从事各类国家鼓励类产业的企业，在2020内减按15%的税率征收企业所得税。是什么意思？

◇ western development policy: a new round of western development, the country's total investment will reach 3 trillion yuan. Enterprises engaged in industries encouraged by various national in 2020 within the 15% reduction in corporate income tax rate.

Copyright: the development of western China Policy: In the New Round in the development of western China, the investment will be up to $3,000,000,000,000 . Engaged in various countries to encourage the type of industry, and in 2020, 15 per cent of the income tax.

◇ The Western development policy: in the new Western development in the country with a total investment of 3 trillion yuan. Enterprises encouraged industries engaged in various countries, within the 2020 reduced enterprise income tax is levied at a rate of 15%.