今年3月,在韩国首尔举行了第二届核安全峰会,核安全峰会是旨在倡导核安全和打击防范核恐怖主义的全球性峰会.下列关于核能的说法正确的是( )
A:核能是一种可再生能源
B:核反应堆将核能转化为化学能
C:核电站是利用核裂变释放的核能
D:开发核能即使有核泄漏也是安全的
一个实验小组在“探究弹力和和弹簧伸长的关系”的实验中,使用两条不同的轻质弹簧a和b,得到弹力与弹簧长度的图象如图所示.下列表述正确的是( )
①甲的质量;
②水对乙容器底部的压强;
③把一个底面积为0.02m2,高0.3m圆柱体A(已知r水>rA)先后放置在正方体甲上和乙容器的水中,甲对地面压强的增加量与水对乙容器底部的压强增加量相等,求A物体的质量.
Hello! I'm an American girl. My first name is Lucy. My last name is White. I'm in No.12 Middle School. My father and mother are in No.12 Middle School, too. They are English teachers. My brother is in Nankai University(大学). His name is Tony. I have a Chinese teacher. Her name is Wang Yan. She can speak (说)very good English. She is a good teacher.
为纪念在塞浦路斯举行的国际会议而发行的梭伦纪念邮票,上面印有梭伦的名言“避免极端”(Nothing in excess)。梭伦改革的措施最能体现他这一主张的是( )