题型:问答题 简答题 —Hi, John, long time not see you! Where have you moved to live?—In other side of the city. I _______ in this neighborhood for almost 15 years.[ ]A. lived B. have lived C. had lived D. had been living 查看答案
题型:问答题 简答题 已知硫酸的化学式为H2SO4,试求:(l)硫酸中硫元素的质量分数(2)98g硫酸跟多少克水的含氢量相等(3)36g水中含氧元素的质量为多少?(4)多少克水中含氢元素5g? 查看答案