After ____ seemed like hours he came out with a bitter smile.A. which B. it C. what D. that
17. By this time next summer, you _____ a high paying job. But I will still be studying. A. will find B. are found C. have found D. will have found
小明利用光具座、凸透镜、蜡烛、火柴、光屏，做“探究凸透镜成像的规律”的实验．（1）一束平行光线经过凸透镜折射后的传播方向如图甲所示，由
我是在__________的环境中捉到鼠妇用于实验的。
▲Hong Kong’s pop star Kelly Chart will have a concert in Hong Kong this month．She has been working on it for two years．She will dance with a group of 40 dancers．Chan is going to wear a dress
长期以来人们只注重水稻培育品种的产量及质量，却忽略野生品种的保存。近年来有学者的实验结果发现，受到某些细菌感染的野生品种水稻有40％的存
右图是国民政府某一时期发行的一套纸币的面值之一。该套纸币的发行 A．推动了国统区经济的健康发展 B．沉重打击了中国的民族工业
下列哪组糖类物质能分别对应 ①存在于RNA中而不存在于DNA中的糖类 ②存在于叶绿体中而不存在于线粒体中的糖类 ③存在于动物细胞中而不存在于植物
