题目

下列金属中，活动性最弱的是                                    （      ） A．Mg         B．Al           C．Zn           D．Fe   答案：D1．20．Why do they hold a party？A．Because it's Linda's birthday．B．Because Linda works well．C．Because they want to show their thanks．21．How long has Linda been teaching here？A．For two years．   B．For three years．   C．For seven years．22．Where will the party be held？A．In the classroom．   B．In the first building．   C．In the meeting room．