31.
My wife left and then I arrived home.
When I ……..………………………………………………….……………
32.
I can’t go out with you tonight because I have to finish my report.
But if I didn’t ……….. …………………………………………………….
33.
The police have decoded the criminals’ messages.
The criminals’………………………………………………………………
34. We have never faced such a complicated problem.
This is …………………………………………………….………………
35. Our journey to Siem-riep lasted for twelve hours.
It …………………………………………………………….
36. The terrible earthquake destroyed the dam.
The dam ………………………………………………………………………