Research _____ that over 81% of teachers are dissatisfied with their salary.

A．contrasts

B．indicates

C．highlight

D．reveal

食物中缺乏烟酸，会引起的临床症状是______。

A．脂溢性皮炎

B．上皮角化

C．脚气病

D．腹泻

E．癞皮病