A:said
B:was saying
C:was said
D:had been said
如图,将充满CO2的试管倒扣在滴有紫色石蕊的蒸馏水中,一段时间后,下列实验现象描述正确的是( )
①试管内液面上升 ②试管内溶液变红
③试管内液面不上升 ④试管内溶液变蓝 ⑤试管内溶液不变色.
Sanya is ____ in winter. It's ____ than many other cities in China. (warm)
如下流程是某同学鉴别NH4HCO3、NH4Cl、KCl三种化肥的过程,其中试剂甲和乙分别可能
—We haven't seen the worst of it yet. Even stronger wind ________ tonight.