1. engage ineg: He was engaged in medical research. 他从事于医学的研究2. 你也可以用些小词，很多时候英语不是非要用很高深的词语的，比如从事，你就可以用doeg：People do farming, grazing or forestry. 人们或从事农耕,或从事放牧,有的则从事林业3. 有的时候从事这个词也可以不翻译出来，只是在中文表达上有eg：She' s very creative ; she writes and paints. 她很有创作能力,既从事写作又从事绘画. 希望对你有所帮助，谢谢
保证: [ bǎo zhèng ] guaranteeRelative explainations: Examples:1. 美利坚合众国保证合众国各州实行共和政体。 The United States shall guarantee to every state in this union a republican form of government.2. 雾天我们不能保证火车准时到达。 We cannot guarantee the punctual arrival of trains in fogy weather.3. 我向你保证。 I assure you.4. 医生们在努力保证早产婴儿成活方面热情很高。 The doctors were zealous in their efforts to ensure the survival of premature babies.5. 人们应经常洗澡以保证个人卫生。 People should wash regularly to ensure personal hygiene.6. 这药保证能让你好好睡一觉。 This medicine will ensure you a good night's sleep.7. 你愿意当你弟弟的保证人吗？ Are you willing to stand surety for your brother?8. 我可以向你保证，你儿子在这里会很快乐的。 I can assure you that your son will be happy here.
小小miffy
