题目

X、Y、Z、W有如图所示的转化关系，则X、Y可能是       ①C、CO                     ②AlCl3、Al(OH)3        ③Fe、Fe(NO3)2                      ④Na2CO3、NaHCO3       A．①②③④               B．①②                      C．③④                      D．①③ We should give a hand to ________ poor when they need help in life.A.a B.an C.the D./