du ◆a~ student笨学生 ◆be~ at mathematics对数学不开窍 ◆ His ears have become~.他的听觉不灵了。 ◆| m rather~ about food.我吃东西味觉不灵。 ◆a~ache隐痛 ◆a~ speaker干巴巴的演说者dull  a ~ student 笨学生  be ~ at mathematics 对数学不开窍  His ears have become ~. 他的听觉不灵了。  I’m rather ~ about food. 我吃东西味觉不灵。  a ~ ache 隐痛  a ~ speaker 干巴巴的演说者