be careful；读音：英 [bi: 'keəfl] 美 [bi: 'keəfl]；解释：当心, 注意；列句：；1.Be careful about what you say.；对你所说的话要小心。

；2.You should be careful when making a promise.；你应当谨慎做出承诺。；3.Be careful!；一定要小心！；4.Be careful crossing the road.；过马路要当心。；5.Be careful of that viper; he is dangerous.；小心那个阴险的人，他很危险。；6.Be careful of that chair; it's a bit rocky.；当心，那椅子有些不稳。；7.Be careful when you cross the road.；过马路时要当心。；8.Be careful not to lose too much liquid by evaporation.；小心，不要因为蒸发作用而失掉过多的水份。