1. bad,作形容词,意为”令人不愉快的,坏的,质量差的,有害”等I'm having a really bad day.我今天倒霉透了。Those shoes are bad for her feet.那双鞋会伤她的脚。2. bad-tempered,作形容词,意为”易怒的,发脾气的”,例如:She gets very bad-tempered when she's tired.她累的时候就爱发脾气。They walked in bad-tempered silence.他们心情很糟,一言不发地走着。3. back,作名词、形容词、副词或动词,意为”背,背部,后面的,向后,在背面,后退,帮助,支持“等He stood with his back to the door.他背对着门站着。We were sitting in the back row.我们坐在后排。He turned and looked back.他转身向后望。4. background,作名词,意为”背景,出身背景,经历”等Programs can be left running in the background.程序可以在后台运行。The job would suit someone with a business background.这项工作适合有商务经验的人。5. backwards,作副词,意为”向后,朝反方向”等The diver flipped over backwards into the water.潜水员向后翻身入水。She lost her footing and fell backwards into the water.她脚未站稳,向后一仰掉进水中。