题干
We thought of selling this old furniture, but we've decided to ______ it. It might be valuable.
A：hold back to
B：hold on to
C：hold up to
D：hold in to
答案(点此获取答案解析）
B
中的氯离子浓度与50 mL 1 mol·L-1的AlCl3溶液中氯离子浓度相等的是