进行光照强度的调节，必须要求每平方米使用60 w的光源，并且要使光源离地2m高。( )
参考答案：对
She showed the visitors around the museum, the construction had taken more than three years.
A．for which
B．with which
C．of which
D．to which
我国的《公路沥青路面再生技术规范》建议水泥等活性填料一般不超过（）
A.1%
B.1.5%
C.2%
D.2.5%
