涡轮流量计的涡轮是用高导磁系数的碳素钢材料制成的。
参考答案：错
解析：涡轮流量计的涡轮是用高导磁系数的不锈钢材料制成的。
为什么鼠笼感应电动机转子采用斜槽？
A municipal bond selling at 12% above par offers a yield of 3.2%. A taxable Treasury note selling at an 8% discount offers a yield of 4. 6%. An investor in the 32.5% tax bracket wishes to purchase an equal dollar amount of both bonds. The after-tax yield of the two-bond portfolio is closest to:（）
A. 2.63%.
B. 3.90%.
C. 3.15%.
