business 指包括售货、购货、换货在内的综合商业活动，方式可以是批发或零售。
commerce 多指大规模的买卖或易货关系。
trade 普通用词，含义广。既可指某种具体的商业又可指广泛的贸易。
bargain 多指买卖双方通过谈判、协商就商品质量、数量、价格等项达成协议所成的生意。
deal 口语用词，指买卖双方经过交涉达成协议成交。
参考例句
1. Our company trades with many foreign companies. 我们公司和许多外国公司进行贸易。
2. My major was Economics and Trade. 我主修的是经济与贸易。
3. He often trade stamps with others. 他经常与别人对换邮票。
英英解释
n.
1. the commercial exchange (buying and selling on domestic or international markets) of goods and servi
2. people who perform a particular kind of skilled work
3. an equal exchange
4. the skilled practice of a practical occupation
5. a particular instance of buying or selling
6. the business given to a commercial establishment by its customers
7. steady winds blowing from east to west above and below the equator v.
1. engage in the trade of
2. turn in as payment or part payment for a purchase
3. be traded at a certain price or under certain conditions
4. exchange or give (something) in exchange for
5. do business; offer for sale as for one's livelihood
