砂砾石和砂的填筑标准应以( )为设计控制指标。
A．相对密度 B．相对压实度C．相对含水量 D．相对湿度
参考答案：A
Mr. Green has made another wonderful discovery, ______ great
importance to science.
A．which I think is of
B．which I think it is of
C．that I think is of
D．I think which is of
简述市场经济体制有效运行的主要前提条件。
