It is also worth noting that in 1985, the financial accounting standards board released the concept of income from the concept framework (SFAC)NO. 6. In 1989, the international accounting standards board's framework for preparing and providing financial statements made clear that benefits also included unrealized gains. In 1997, FASB's FASB N0.130 required a full return; In 1998, IASC's IAS NO.1 required the preparation of an equity change table, a comprehensive income statement, including the benefit of reflecting corporate assets. In 1946, the famous British economist J.R. hicks, in value and capital, developed the concept of income into a general concept of economic gain. He argues that the real purpose of computing revenues is to make people aware of the amount of money they can spend without making them poorer. Accordingly, he gave a generally accepted definition of "the maximum amount of consumption that a person can spend at the end of the term, at the same level of prosperity". Hicks's definition, though primarily for personal gain, applies to businesses as well. In the case of the enterprise, according to this definition, the enterprise income can be understood as the maximum amount that can be allocated in the enterprise cost accounting period under the same amount of capital at the end of the term and the beginning of the period. Gas vehicles mainly include liquefied petroleum gas vehicles (LPG vehicles or LPGV) and compressed natural gas vehicles (CNG cars or CNGV). As the name suggests, LPG cars are fueled by liquefied petroleum gas (LPG) and CNG is powered by compressed natural gas. The CO emission of gas vehicles is more than 90 percent less than the gasoline car, the hydrocarbon emission reduction is more than 70 percent, and the nitrogen and oxygen emission reduction is more than 35 percent, which is the current relatively practical low emission vehicle.