圈出得数等于 2 的算式

计算各算式结果：
1. $\frac{3}{4} + \frac{7}{4} = \frac{10}{4} = 2.5$
2. $\frac{3}{13} + \frac{9}{13} = \frac{12}{13} \approx 0.92$
3. $\frac{5}{2} - \frac{1}{2} = \frac{4}{2} = 2$
4. $\frac{5}{6} + \frac{1}{3} = \frac{5}{6} + \frac{2}{6} = \frac{7}{6} \approx 1.17$
5. $8.4 ÷ 4.2 = 2$
6. $3 - \frac{6}{6} = 3 - 1 = 2$
7. $\frac{7}{5} + \frac{3}{5} = \frac{10}{5} = 2$
8. $0.25 × 8 = 2$
9. $\frac{5}{7} + \frac{8}{9} = \frac{45}{63} + \frac{56}{63} = \frac{101}{63} \approx 1.60$
10. $0.2 ÷ 0.5 = 0.4$
得数等于2的算式：
$\frac{5}{2} - \frac{1}{2}$，$8.4 ÷ 4.2$，$3 - \frac{6}{6}$，$\frac{7}{5} + \frac{3}{5}$，$0.25 × 8$
（注：按题目要求圈出上述算式，此处以文字形式列出）