Замените
определительные придаточные предложения оборотом с причастием I.
1. When I travel I
always reserve accommodation in advance.
2. We are going to contact the firm which is advertising
the latest modal of the boilers.
3. When
the director came into the office he saw several people who were
waiting for him.
4. When we write a cable we try to use as few
words as possible.