3.1-2-2、 <img src="https://static.zxtiku.com/wangke/imgs/topic/fe30462dde74355f6f5da5a5f0bc8fc4.jpg"/> =( )。 A. <br/> <img src="https://static.zxtiku.com/wangke/imgs/topic/c17a404c38518a5de3697468f12f4f5d.jpg"/> B. <br/> <img src="https://static.zxtiku.com/wangke/imgs/topic/09068e850011fcfec11dd80b5e89b093.jpg"/> C. <br/> <img src="https://static.zxtiku.com/wangke/imgs/topic/5e6444cded7c8bab9302763a2a7dca0b.jpg"/> D. <br/> <img src="https://static.zxtiku.com/wangke/imgs/topic/67b1afa7cfef9aaaf1d25682326fb823.jpg"/>