4. By 1 o'clock yesterday I (to meet) Bessy at the airport and at 3 o'clock we (to go) to the Russian Museum.

Solution:

• 4. By 1 o'clock yesterday I had met Bessy at the airport and at 3 o'clock we were going to the Russian Museum.

Explanation: Meeting Bessy was completed by 1 o'clock (Past Perfect). Going to the museum was in progress at 3 o'clock (Past Progressive).