Finish the second sentences so that it has the same meaning as the first one

Finish the second sentences so that it has the same meaning as the first one
1. It was not until the building was almost burned down that the firemen arrived
The firemen....
2. It was not until the spring came that the ice on the lake thawed
The ice...
3. Julia didn't notice until I had shouted her
Not until...
4. Astronomy is one of Tan's main amusements
Tan finds