单选题 After you ______ the attached form, please send it to us within 7 working days to be eligible for our two-year warrant program.
A. will complete
B. completed
C. having completed
D. have completed

【正确答案】 D

【答案解析】高级问题这里考查的是时间/条件状语从句的用法。合适的是现在时或现在完成时，选项里没有现在时，所以选择现在完成时D选项。请牢记以下句式：“引导时间/条件状语从句的连词+主语+现在时/现在完成时，主语+将来时(或祈使句)”。
[高频词语] attached 附上的 working days 工作日 be eligible for 有……资格的