Speaker A: Excuse me, can you tell me where the Prince’s Building is
Speaker B: ().

A. The Prince’s Building Why do you want to go there

B. Sure, if you like, I can show you how to get there.

C. Well, turn to the left at the first corner after the crossroads. It’s there near the corner.

D. Strange! What’s going on there Three people have asked me how to get there.

一个电阻两端加10V电压时，通过它的电流为0.2A，这个电阻的电阻值为______Ω．如果将它两端的电压增大到15V，则通过它的电流为______A．若这个电阻两端的电压减小到零，这个电阻的电阻值为______Ω．