某同学为检测温度对种子发芽率的影响,将三个培养皿各放50粒小麦种子并标号1、2、3,然后分别置于15℃、25℃和40℃的环境中,其它条件均适宜.如表
利用乳酸菌发酵制作的食品是 A.酱油 B.面包 C.酸奶
“17世纪和l8世纪初,西方人了解中国的历史、艺术、哲学和政治后,完全入迷了。”然而,“18世纪来,欧洲人对中国的自然资源更感兴趣。”导致这
He was a professor. At the age of 90, he still worked eight hours every day regardless 61 the weather. His secretary said: “He was extremely old, but he forced himself to walk from his livi
---It is required that you____ change the plan. ---Oh, no! Why____ I follow you again? A. must, must B. can, need C. need, should D. should, must
在室温下,下列五种溶液: ①0.1mol/L CH3COONa ②0.1mol/L CH3COONH4 ③0.1mol/L NH4HSO4 ④0.1mol/L NH3·H2O和0.1mol/L NH4Cl混合液 ⑤0.1mol/L NH
工业上冶炼金属一般用热分解法、热还原法和电解法,由于金属的化学活动性不同因此采用不同的冶炼方法。你认为选择的原则主要是依据A.金属阳离子
(08年长郡中学一模理)(12分)已知在多面体ABCDE中,AB⊥平面ACD,DE∥AB,AC = AD = CD = DE = 2,F为CD的中点.(Ⅰ)求证:AF⊥平面CDE;(Ⅱ)求平面ABC和