题目

Only when she left her parents and went to college in a faraway city         how much she loved them．     A．she realized   B．she had realized  C．had she realized D．did she realize 答案：D下面的相对分子质量的计算正确是的（　　） A、2CO2：2×12×16×2=768B、2NH3：2×14+1×3=31C、2H2O：2×（1×2+16）=36D、CO（NH2）2：12+16+14+1×2×2=46