所谓环境威胁,是指环境中一种不利的发展趋势所形成的挑战,企业对那些严得性大且可能性大的威胁应制定应变对策,一般有()等选择。 ["对抗","观察","削弱","转移"]
黄酮又叫黄碱素,其弱碱性来源于() ["5位OH","7位OH","苯环","1位氧原子","吡喃酮环"]
四色印刷的四色是指()。 ["红、绿、蓝、白","红、绿、蓝、黑","黄、品红、青、白","黄、品红、青、黑"]
多单枝,细小弯曲如钩,过桥较短() ["A.味连","B.雅连","C.云连","D.峨眉野连","E.短萼黄连"]
提取黄酮苷元宜用溶剂为() ["冷水","乙酸乙酯","甲醇","0.1%盐酸","沸水"]
配电屏宜采用符合我国有关国家标准规定的产品,并应有()和()。