Salut,
1) had already reached
2) had stolen
3) had watched
4) had tried
5) had begun
6) had eaten
7) had snowed
8) hadn't studied
9) had left
10) had broken
11) had drunk
12) hadn't locked
13) hadn't hidden
14) had forgotten
15) had never visited
16) had taken
17) had escaped
1-had already reached
2-had stolen
3-had watched
4-had tried
5-had begun
6-had eaten
7-had snowed
8-had not studied
9-had left
10-had broken
11-had drunk
12-had not locked
13-had hidden|hid
14-had forgotten
15-had never visited
16-had taken
17-had escaped