12. While Bob... (chop) the meat, his wife (pe

12. While Bob was chopping the meat, his wife was peeling potatoes.

Пояснение: Past Continuous используется для описания двух одновременных действий, происходивших в прошлом. Боб резал мясо, в то время как его жена чистила картошку.

Ответ: While Bob was chopping the meat, his wife was peeling potatoes.