将下列句子改为含有同位语从句的复合句
1.We are a bit worried when we realize that great Auks and Quaggas are extinct.
2.Do you know what we can do with these waste materials?
3.They are arguing about whether we can clone human beings.
4.Every one should believe that nature should never be destroyed
5.She has promised to make experiments on cloning bison.