70pc是多少ly？
70pc = 228.3095ly
是228.3095ly，所以说成228ly也没问题——四舍五入的误差在0.5%以内。
反过来，70ly是多少pc？
70ly = 21.4621pc
计算公式: ly = pc × 3.261564
该数值前后的 pc → ly
25 pc81.5391ly
30 pc97.8469ly
35 pc114.1547ly
40 pc130.4626ly
45 pc146.7704ly
50 pc163.0782ly
55 pc179.386ly
60 pc195.6938ly
65 pc212.0016ly
70 pc228.3095ly
75 pc244.6173ly
80 pc260.9251ly
85 pc277.2329ly
90 pc293.5407ly
95 pc309.8486ly
100 pc326.1564ly
105 pc342.4642ly
110 pc358.772ly
115 pc375.0798ly
120 pc391.3877ly