—I read them twice a week.
A:How long
B:How soon
C:How far
D:How often
①AlCl3溶液和NaOH溶液
②Ca(HCO3)2溶液和NaOH
③NaAlO2溶液和NaHSO4溶液
④Al2(SO4)3和氨水
⑤AgNO3溶液和氨水.
坐在温馨的物理考场,仔细想想:你平时走路的步幅约为50____,上体育课时你跑100m所需时间约为16____(填上合适的物理量单位).
选择与图片对应的句子( )