在第二次工业革命中，关于交通运输工具的革新，搭配正确的是（ ）
A：蒸汽机──火车
B：发电机──轮船
C：蒸汽机──飞机
D：内燃机──汽车
Amy：Who's that ____ (bay boy)?
Chen Jie: He's ____ (me my) brother.
Amy: Is she ____ (you your) mother?
Chen Jie: Yes , ____ (She she ) is.
Amy: Is he ____ (you your) father?
Chen Jie: No, he isn't. ____ (he's He's ) my teacher!
遗传物质的基本单位是（）
