就病因角度而言,龋病也可称为是牙体硬组织的
A.病毒感染性疾病B.细菌感染性疾病C.真菌感染性疾病D.支原体感染性疾病E.衣原体感染性疾病
参考答案:B
Whenever his mother spoke to him, ____ was fairly often, he would talk on and on without giving her a chance to speak.
A.that
B.what
C.which
D.who
试论控制层间温度有何意义?