6.
下列物质与其用途完全符合的是\(\rm{(}\) \(\rm{)}\)
\(\rm{①Na_{2}O_{2}-}\)供氧剂 \(\rm{②}\)晶体\(\rm{Si-}\)太阳能电池 \(\rm{③AgI-}\)人工降雨 \(\rm{④NaCl-}\)制纯碱\(\rm{⑤Al_{2}O_{3}-}\)焊接钢轨\(\rm{⑥NaClO-}\)消毒剂\(\rm{⑦Fe_{2}O_{3}-}\)红色油漆或涂料 \(\rm{⑧SO_{2}-}\)食品漂白剂 \(\rm{⑨NH_{3}-}\)制冷剂.