五、完成下列句子。 35’
1. 商业广告是一种人们为了推销某商品或服务而花钱做的广告
A commercial advertisement is one which _______________________________________.
2. 公益广告往往是免费投放的，其目的是就健康、安全或其他影响到公众利益的问题对老百姓进行教育。
PSAs are often placed for free, and __________________________ about health, safety, or any other issue which affects public welfare.
