Complete the sentences with the past perfect of the verb in brackets:
1.Kevin (go)..............home by the time I arrived.
2.Ethan suddenly realized that he (leave)..................his laptop on the train.
3.Mum was annoyed because I (not clean).............my room.
4...................they(study)..........English before they went to the USA.
5.We were hungry because we (not eat)...............................
6.My phone didn't work because I (not charge).................it
7.Why didn't you want to watch the film? -..................you(see)..........it before?
8.Sally was embarrassed because she )forget).................her dad's birthday.
9.I(never/see).......................such a beautiful beach before I went to Kauai.
10.I did not have any money because I (lose)..........my wallet
11.Tony knew Istanbul so well because he (visit)..........................the city several times.
12.We were not able to get a hotel room because we (book)...........in advance.