细胞分裂素合成的主要部位是( )
李老师和王老师晚上散步,他们同时从家里出发,相向而行,两家相距1140米。同时李老师家的小狗也跟了出来,而且跑在了前面,去找王老师,当小狗和王老师相遇后,立即返回跑向李老师,当遇到李老师后立即返回跑向王老师……,这样不停地跑来 跑去,一直到两人相遇。已知李老师每秒钟走1米,王老师每秒钟走0.9米,小狗每秒钟跑2米,请你算一算,小狗一共跑了多少米?
董诚,一位普通职工,几十年如一日,坚守“把有限的生命投入到无限的为人民服务中去”的信念,被群众亲切地称为“咱身边的活雷锋”。他耸起“雷锋110”灯塔照亮人们的心灵。他的事迹说明( )
①不计较代价与回报的奉献精神,是社会责任感的集中表现
②助人为乐、服务社会,是我们义不容辞的法定义务
③热心公益,在奉献中提升自身的价值
④参与社会公益活动,有利于营造“我为人人,人人为我”的社会氛围
____This is a picture of my uncle's family. These are my uncle and aunt. Those are their children(孩子),Li Ming and Li Ling.
____ Look at the picture. This is my friend. His name is Jack.
____Here's a photo of my family. These are my grandparents. Those are my parents. This is me.
____Look at this picture. This is my father and that is my mother.
____ Look at the three boys. They are my cousins and me.
A B C
D E
如图所示,斜面体固定在水平面上,倾角为θ=30°,质量为m的物块从斜面体上由静止释放,以加速度a= g2 开始下滑,取出发点为参考点,则图乙中能正确描述物块的速率v、动能Ek、势能EP、机械能E、时间t、位移x关系的是( )