氨茶碱的适宜浓度为（）
A.10～20mg/L
B.20～25mg/L
C.25～30tug/L
D.25mg/L
E.5~10mg/L
参考答案：A
—______ do you think is the ______ in your factory.
—Jim is[ ]
A. What, most creative
B. Who, more creative
C. Which, creativer
D. Who, most creative
与基坑明挖法相比，盖挖法施工最显著的优点是( )。
A．施工成本较低B．出土速度快C．围护变形小D．可尽快恢复交通
