井下冒顶埋（堵）（）人及以上是淮北矿业重大涉险责任事故界定标准规定的内容之一。
A.1
B.2
C.3
D.4
参考答案：C
用配方法解方程：x2+mx+n=0．
The house I grew up _____ has been taken down and replaced by an office building. [ ]
A. init
B. in
C. in that
D. in which
