可行性研究报告中投资估算的精确度一般应达到()。
A．±10%
B．±5%
C．±20%
D．±15%
参考答案：A
—_____ your mother go fishing?
—No, she didn't. She went shopping. [ ]
A. Does
B. Is
C. Did
D. do
说明制碱塔反应区上移或下移可能会造成的后果？
