施工现场用电工程中，PE线上每处亘复接地电阻值不应大于（）。
A、4Ω
B、10Ω
C、30Ω
D、100Ω
参考答案：B
选择性偏差
—I wonder how much you _______for your services.
---Well, the first two are free while the third costs $30 .
A．bargain
B．charge
C．offer
D．donate
