A:铝具有优良的抗腐蚀性 4Al+2O2 △_ 2Al2O3
B:氢气作高能燃料 2H2+O2 点燃_ H2O
C:用铁桶配制农药波尔多液 Fe+CuSO4═FeSO4+Cu
D:证明铜活动性的比银强 Cu+2AgNO3═Cu(NO3)2+2Ag
(a+5)+b=a+(____+____)
交通方式
频数(人数)
频率
公共汽车
m
0.25
小车
24
0.20
摩托车
36
n
自行车
18
0.15
其它
12
0.10
请根据图表信息解答下列问题:
下列实验正确的是( )
A: Who's that ____( boy / girl) ?
B: He's my brother.
A: Is the ____( man / woman) your mother?
B: Yes, she is.
A:____ (What's / Who's) that man?
B: Guess.
A: Is ____( he / she) your father?
B: No, he isn't.____ (She's / He's ) my teacher.