1. Always proofread completed letters very carefully. Consult dictionary when necessary or in doubt.
    完成的书信一定要很小心地校对，有必要或怀疑时查典。

2. Always proofread completed letters very carefully. Consult dictionary when necessary or in doubt.
    完成的书信一定要很小心地校对，有必要或怀疑时查典。