题目

To tell you the truth, so far we _______ 10,000 such kind of expensive cars. A. produced B. had produced C. produce  D. have produced 答案：D17．300mL 0.1mol•L-1的氯化钾溶液与100mL0.1mol•L-1 的氯化铁溶液的氯离子的物质的量的浓度之比是（　　）A．2：1B．1：1C．2：3D．1：3