下面属于冷光源的是（）
A.太阳
B.白炽灯
C.发光三极管
D.卤钨灯
参考答案：C
He came to my lecture every week, but his look ___ that he was not really interested.
A．expresses
B．described
C．explained
D．suggested
触电后，对人体的伤害程度由流经人体的电流、途径和时间三要素决定。（）
