第五句：
中国还积极参与国际合作，为全球环境保护做出了重要贡献。
译文一：Additionally, China has actively participated in international cooperation and made significant contributions to global environmental protection.
思路：描述已发生并将持续的动作，时态可以用现在完成时，也可以用一般现在时，表示是中国当前一贯的行为；
“还” 可译为 also 或 additionally，置于助动词后或句首。
译文二：China is also actively engaged in international cooperation, contributing significantly to global environmental protection.
译文三：China also takes an active part in international cooperation and contributes significantly to global environmental protection.
注：原句包含两个动作：“参与”和“做出贡献”。两者可以是并列关系，用并列句翻译，如译文一和译文二；也可以是主次关系，另一个变成非谓语动词表示状语，如译文二。
