=IF(AND(D7="矩形风管"),(F7+G7)*2/1000*L7,IF(AND(D7="罩子"),(F7*G7/100000+(F7+G7))*2/1000*L7,IF(AND(D7="集风箱"),(F7*G7/1000000+F7*L7/1000000+G7*L7/1000000)*2,IF(AND(D7="盲板"),F7*G7/1000000,IF(AND(D7="百叶"),L7,IF(AND(D7="软接"),(F7+G7)*2/1000*L7,IF(OR(D7="矩形风管",D7="罩子",D7="集风箱",D7="百叶",D7="盲板",D7="软接"),""))))))),条件不符合的显示FALSE,如何显示空的,或者有没有优化的方案,条件还要继续往下加