5 react

1 [I, Ipr] ~ (to sb/sth) behave differently or change as a result of sth; respond 作出反应; 回应
    Pinch me and I will react. 你要掐我我就有反应.
    People can react badly to certain food additives. 有的人对某些食物添加剂产生严重变态反应.
    react positively/negatively to a suggestion 对一项建议作出赞成的[反对的]回应
    She reacted to the insult by turning her back on him. 她受他侮辱之後就不再理睬他了.
2 [I, Ipr] ~ (against sb/sth) respond to sb/sth with hostility, resistance, etc 反对; 反抗; 反动
    react strongly against tax increases 强烈反对增税
    Will the people ever react against this dictator? 有朝一日人民会起来反抗这个独裁者吗?
3 (chemistry 化)
(a) [I, Ipr, Ip]
~ with sth; ~ (together) (of substances) undergo changes by coming into contact with sth (指物质)起化学反应
    Iron reacts with water and air to produce rust. 铁与水和空气起化学反应而生 .
    Sodium and water react (together). 钠和水能起反应.
(b) [Ipr] ~ on sth have an effect on sth or produce a change in sth 对某事物有影响; 使某事物产生变化
    How do acids react on metals? 酸对金属起什麽反应?