题干
A great number of people were killed in the big fire, and the number of the people who _____ missing _______still increasing.
A：were; wa
B：are; i
C：were; i
D：are; wa
答案(点此获取答案解析）
B
．现高温加热铝粉和氧化铜混合物，使其充分反应．为检验反应后氧化铜是否有剩余，取少量反应后的固体，加入足量稀硫酸，反应后将锌片插入上层溶液中．