简述玻璃纤维主要优缺点?
假如生产一双皮鞋的社会必要劳动时间是4小时,售出后收入60元.某一生产者率先提高劳动生产效率一倍,即2小时生产一双,他用4小时生产同样的皮鞋售出收入是(). ["30元","60元","120元","90元"]
党的十七大开幕式的主持人是谁() ["A、李长春","B、吴邦国","C、胡锦涛","D、温家宝"]
最早发现疯牛病的国家是() ["美国","英国","法国","西班牙"]
万古霉素属于哪类药物() ["林可霉素类","β-内酰胺类","大环内酯类","多肽类"]
如何加快果蔬的复水速度?