Although the film star has got a tight schedule these days, our boss is still _________ to have him invited to the party for the promotion of our new product.

A．concerned

B．determined

C．frustrated

D．annoyed

当冷端温度保持一定时，热电势的方向和大小与热电极的（）和工作端的温度有关。

A.粗细

B.长度

C.温度

D.材料