在可行性研究阶段，投资估算的允许误差率应控制在( )以内。
A．±10%
B．±15%
C．±20%
D．±30%
参考答案：A
--- What did the professor tell you to do?
--- I had to write a ________ report.
A．three-thousand words
B．three thousands word
C．three-thousand-word
D．three-thousand-words
什么是“永”字八法？（3分）
--- I had to write a ________ report.