1. We went to the zoo and saw three walruses there. (Допускается форма walrus для множественного числа - как и в случае со словом fish, но walruses - более употребительна.)
2. John studies prevention of diseases.
3. Treat her politely please, she's very shy.
4. You should be brave enough to practice conditioning to the cold. (более употребимый вариант - cold conditioning)
5. After you cure one disease, you may get another.
6. I have visited some hot springs in the city of Bath.
7. The prescription was written in bad handwriting.
8. An ecological catastophe was prevented a year ago.
