—I'd like ________ the after-school club,  but I'm not sure what I should do.

—What do you like ________?[ ]

A. to join, do  

B. to join, doing    

C. joining, to do    

D. joining, doing

硼氢化钾—硝酸银分光光度法测定水中痕量砷，发生砷化氢时，如果反应液中有气泡产生，可加入适量乙醛消除。