(1)3.01×1022个OH-的物质的量为 质量为 ,这些OH-与 mol NH3的质量相等,与
()(本小题满分12分)已知定点,动点满足条件:,点的轨迹是曲线,直线与曲线交于、两点。如果。(Ⅰ)求直线的方程; (Ⅱ)若曲线上存在点
澳洲罗宾华伦和巴里·马歇尔两位科学学家获得了2005年的诺贝尔生理学或医学 奖。他们发现了胃炎、胃溃疡和十二指肠溃疡是由幽门螺旋杆菌感染造成
Finding a job as a singer was the reason ______ she moved.. A. where B. that C. by which D. for which
He is a very honest official and never _____ any gifts from the people who sought his help. A. accepted B. received C. carried D. excepted
下列加点字注音有误的一项是( ) A.亘古(gèn) 淹没(mò) 模式(mó) 锲而不舍(qiè) B.钦佩(qīn) 汲取(jí) 炫目(xuàn) 哄堂大笑(
将某一经3H充分标记DNA的雄性动物细胞(染色体数为2N)置于不含3H的培养基中培养,该细胞经过两次连续分裂形成4个大小相等的子细胞。下列有关的说