题干
Our teacher told us __________.
A：what life on Mars is like
B：how life on Mars is like
C：what life on Mars was like
D：how life on Mars was like
答案(点此获取答案解析）
C
)3溶液V mL中含a g Al3+，取出V/4 mL溶液稀释成4V mL后，SO42－的物质的量浓度为