重点讲解：
1. contribute to （为…）做贡献；
例句：Many specialistic techniques contribute to archaeology.
许多专业技术对考古学作出贡献。
2. sign up 签署；签约；报名；
例句：But not all parts of the industry hae signed up.
但并不是行业内的所有企业都签署了此协议。
3. be aimed at 旨在；目的是；
例句：Analyst said the move was aimed at making the company more attractive to international investors.
分析人士说，这个举动是为了让公司对国外投资者更具有吸引力。
4. prevent sb. from doing sth. 阻止；制止；阻碍；
例句：Ways must be found to prevent the poisonous gases from polluting the air.
一定要找到办法防止有毒气体污染空气。
5. in response 回复；回答；回应；
例句：Shares in financial institutions immediately slumped in response.
作为回应，金融机构的股票随即大幅下挫。
