单选题 Heat is always being transferred in one way or another, ______ there is any difference in temperature.
A. since B. where C. after D. as soon as

【正确答案】 B
【答案解析】[解析] where在句中是连接副词，意为：“在……地方”。题句意为：“凡是有温差的地方，热都会以这样或那样的方式传导。”