多项选择题Generally speaking, a presentation follows the same basic guidelines as preparing for a meeting. ( )
单项选择题甲、乙两瓶酒精溶液分别重30O克和120克；甲中含酒精120克，乙中含酒精90克。问从两瓶中应各取出多少克才能兑成浓度为50%的酒精溶液140克？( )
