单项选择题 酶竞争性抑制作用的特点是 （21/1998）（）

判断题 高压喷射灌浆的施工工序包括造孔、下喷射管和喷射灌浆。

判断题 If, for an imaginary closed economy, investment amounts to $10,000 and the government is running a $2,500 deficit, then private saving must amount to $12,500.