根据下列句子所给汉语意思写出空缺处单词，或根据所给词写出正确形式。
Would you please send a ____________(口信) to him for me?
All of the envelops are made of __________(回收的) paper.
Our premier made outstanding _____________ (贡献) in the field of foreign affairs.
Parents should not show ___________（偏爱）for any one of their children.
I'm very ____________ (谨慎) about expressing my opinions in public.