加热炉所用耐火材料有哪些？
参考答案：有耐火泥、粘土结合高铝浇注料、粘土砖、轻质砖、硅藻土砖、耐火纤维及高温涂料等。
Specific duties are levied （） some physical unit such as dollars per bushel, per kilo, or per metre and ad valorem duties are calculated as a percent of the value of the goods.
A. on the basis of
B. with the basis of
C. on the base of
D. with the base of
国家实行无偿献血制度。提倡18周岁至55周岁的健康公民自愿献血。（）
