详细可行性研究阶段的投资估算,其误差率应控制在( )以内。
A.±15%
B.±20%
C.±30%
D.±10%
参考答案:D
母亲带1岁男孩来院查体,经检查该小儿体格发育正常。
身高应约为( )
A.46cm
B.49cm
C.55cm
D.60cm
E.75cm
Electricity () by the Greeks a good many years ago.
A.was first found
B.was first discovered
C.has first been discovered
D.was seen first