单项选择题 某项目现有三个互斥的投资方案A、B、C，欲从中选择最有利的方案，一个投资方案的投资额及一年后的净收益如下表所示。各方案的寿命期都是一年，一年后的净残值为零。C方案的净现值为( )万元。

未知题型 According to the passage, which is Not True of surveys via the Web?A.They reduce the cost involved in data collection.B.They are secure and easy-to-use in collecting datA.C.They provide more convincing conclusions on the matter surveyeD.D.They face fierce competitions from the traditional survey methods.

未知题型 What makes traditional surveys unscientific according to the second paragraph?A.The sampling is not made strictly randomly.B.The interview has to be conducted face-to-facE.C.Improper questions are often included in a survey.D.Selection of respondents is often a matter of personal decision.