Archie(自动搜索服务工具)实际上是()
A.一个大型的数据库
B.一套检索方法
C.一个管理机构
D.一个数据库和与之相关联的一套检索方法
参考答案:C
—Why does the lake smell terrible?
—Because large quantities of water______.
A.have polluted
B.is being polluted
C.has been polluted
D.have been polluted
计算:9.892-0.112=______.