主产于宁夏的药材是（）
A.枸杞子
B.砂仁
C.豆蔻
D.五味子
E.枳壳
参考答案：A
Tom knew nothing about it his sister told him. [ ]
A. since
B. if
C. until
D. unless
简述新产品开发对企业的意义是什么？
