6. Complete the sentences with the past perfect form of the verbs in brackets.
(Hoàn thành các câu với dạng quá khứ hoàn thành của động từ trong ngoặc.)
1. I didn't have any chocolate because my sister _____ (eat) it.
2. I couldn't buy the magazine because I _____ (forget) to bring my wallet with me.
3. I didn't recognise my cousin. He _____ (grow) a beard.
4. We couldn't get home because we (miss) _____ the last bus.
5. After I (write) the answer, I realised I _____ (make)a mistake.
6. I didn't watch the programme because I _____ (see) it before.
1.had eaten
2.had forgotten
3.had grown
4.had missed
5.had written-had made
6.had seen