小小解说员（解释下列词语）。

(1)相依为命：                                                                                                                                  

(2)欣欣向荣：                                                                                                                                  

(3)郑重其事：                                                                                                                                  

(4)束手无策：                                                                                                                                  

(5)垂头丧气：                                                                                                                                  

(6)胸有成竹：                                                                                                                                 

下列对某气体的实验中：①使澄清石灰水变浑浊；②使湿润的蓝色石蕊试纸变红；③使品红褪色；④通入足量的NaOH溶液中，再滴加BaCl₂溶液有白色沉淀生成，该沉淀溶于稀盐酸；⑤通入溴水中能使溴水褪色，且滴加Ba(NO₃)₂溶液有白色沉淀产生。其中能证明其中有SO₂的是 [ ]

A．都能证明

B．都不能证明

C．③④⑤能证明

D．只有⑤能证明