Country A has produced a new type of fighter su-30, and country B has two different voices on whether to introduce such a fighter. Supporters believe that su-34 has more More powerful ground attack combat capabilities. Which of the following, if true, would most weaken the voice of supporters? ? ['There are other fighters on the market with better performance than the su-34.', 'su-30 is enough to meet the needs of ground attack. At present, what country B needs to improve is its air attack combat capability.', 'There is no actual data showing that the su-34 has a more powerful ground attack capability.', 'At present, there are many frictions between the two countries in bilateral trade, and there will be many practical difficulties in introducing su-34.']