You can find whatever you need at the shopping centre, _____ is always busy at the weekend. [ ]

A. that

B. where

C. what

D. which

彩色电视机自动消磁电路中使用的消磁电阻是（）。

A．负温系数热敏电阻

B．正温系数热敏电阻

C．磁敏电阻

D．光敏电阻