He . documents by the time the boss came.

В данном предложении посмотрим на время, да и на само задание:

Скажем, что в данном случае нет отрицания и тут время Past Perfect!

Значит получаем такое предложение:

He  had prepared documents by the time the boss came.

1. spain and portugal are considered to be good places for summer vacations. 2. christmas is known to be the most popular holiday in britain and the usa 3. patriotic symbols are thought to be very important for national celebrations. 4.thanksgiving day is said to unite many american families for a thanksgiving dinner. 5. the british queen is supposed to be the most important symbol of the country. 6. british football is considered to be the best. 7. americans are said to have more national celebrations that any other nation

я пишу, чтобы претендовать на должность гида летних туров, которая была объявлена ​​на этой неделе в редакции "еженедельного вестника".