下列化学用语不正确的是 [ ]
A．氧元素：O2
B．2个氢原子：2H
C．氧化铁：Fe2O3
D．镁离子：Mg2+
答案：A
Hardly _____ the dormitory the next morning when we _____ we had left our map in the room.[ ]
A. we left; realized
B. did we leave; realized
C. we left; did we realize
D. had we left; realized
查询“学生成绩”表中所有不是姓“李”的学生记录，其SQL语句为： SELECT*FROM学生成绩WHERE姓名______"李%\
