题目

Mary is     girl, but she knows a lot about science.     A. a eight-year-old   B. eight-year-old   C. eight years old    D. an eight-year-old 答案：D15．直接写出得数：7×$\frac{3}{14}$=$\frac{6}{7}$÷6=$\frac{4}{5}$÷$\frac{5}{4}$=$\frac{5}{14}$÷$\frac{5}{14}$=3-$\frac{3}{5}$=$\frac{1}{8}$÷$\frac{5}{2}$=$\frac{1}{3}$×0.15=$\frac{3}{7}$÷$\frac{7}{8}$=4×60%=$\frac{3}{8}$×4$÷\frac{3}{8}$×4=