题目

—It is said that Williams will come to help us. —         we depend him, we have to do most of the work ourselves. A. No matter what degree                 B. Whatever C. However much                          D. However   答案：C已知氢氧化铜为蓝色固体，难溶于水，稀硫酸能与其发生反应，化学方程式为Cu(OH)2 + H2SO4 = CuSO4 + 2H2O。下列说法中，不正确的是 A．反应类型为复分解反应                  B．反应后溶液为蓝色 C．参加反应的两种物质的质量比为1:2       D．反应前后各元素质量均不发生改变