服装材料
参考答案：
是指用以加工成服装产品的全部材料。
_____ you may face, you must gather your courage to finish it. [ ]
A. However a difficult task
B. What a difficult task
C. However difficult a task
D. What difficult a task
烧结空心砖每个密度级根据孔洞及其排数、尺寸偏差、外观质量、强度等级和物理性能分为（）质量等级。
A、三个
B、四个
C、五个
D、六个
