下列说法正确的是:A. 金属钠着火可用煤油扑灭B.将几滴FeCl3饱和溶液滴入氢氧化钠溶液可制备Fe(OH)3胶体C向含有等量NaI、NaCl的溶液中滴加AgNO3溶液,先产生白色沉淀;D. 用浓氢氧化钠溶液和湿润红色石蕊试纸检验某溶液中是否有NH4+
I can’t leave. She told me that I ______ stay here until she comes back.
—— Do you mind my opening the window? It’s a bit hot in here. —— ______ , as a matter of fact
It’s high time you had your hair cut ; it’s getting _______ .
My friend showed me round the town, ______ was very kind of him.
They use computers to keep the traffic _______ smoothly.