绿色食品加工的基本原则包括()原则、()原则、()原则、()原则。
参考答案:可持续发展;营养物质最小损失;加工过程无污染;无环境污染
I ______ the piano quite well, but I haven't had time to play since last month.[ ]
A. will play
B. have played
C. played
D. play
以下哪项不宜火煅()。
A.代赭石、石膏
B.朱砂、琥珀
C.石决明、珍珠母
D.磁石、礞石
E.牡蛎、龙骨