Mr. Barren doesn’t think that all bad language should be allowed. In his opinion, there are ___________ that should be kept up.

A．degrees

B．levels

C．limits

D．standards

具有线路简单、测温灵敏、感温元件稳定“三S”特征的是（）式温度计。

A、热电偶

B、热电阻

C、辐射

D、膨胀