在进行现场压实质量的评定时，施工单位自检人员的检测频率为2000m2检验 ( )点。
A．2 B．4 C．6 D．8
参考答案：D
Samuel Clemens, _____ Mark Twain, because a famous American writer.
A．was known as
B．known as
C．was known for
D．known for
“小华2.5小时走了5千米”，用“2.5÷5”是求______，用“5÷2.5”是求______．
