9.5x0.98____9.5 5.4÷0.98____5.4
2.25÷0.5____2.25x0.5 7.8x1____7.8÷1
“试管婴儿”的培育诞生和嫁接繁殖无核蜜橘在生物学上依据的原理依次是( )