以下图示(注:代表太阳,椭圆形线为地球运行轨迹)最有可能体现谁的成就
A.哥白尼
B.布鲁诺
C.伽利略
D.开普勒
答案:D
(6分)某有机物12g完全燃烧,生成7.2g H2O和8.96L CO2(标准状况下),0.5mol此有机物的质量为30g。求:
(1)有机物分子式
(2)又知此有机物具有弱酸性,能与金属钠反应,也能与碱溶液反应,试写出它可能的结构简式
He______the job well, but he______so careless.
A.had done; had been
B.could do; was
C.could have done; was
D.hadn’t done; had been