我国学者廖泉文创建了“三三三”理论。
参考答案：对
—Do you often play_______ football with your friends?
—No, I don’t like sports. I often play______ piano in my free time.
A. a, the B. the, / C. /, the
只用一种试剂不能鉴别的一组溶液是（ ）
A．BaCl2CuSO4Na2SO4
B．HClNaOHNaCl
C．NaClNaNO3Na2SO4
D．HClAgNO3Na2SO4
