Find the five mistakes and correct them. 1 when i was a kid, we usually go to the mountains during the summer. 2 i used work as a researcher for a drug company. 3 he's lost a lot of weight. he used to weigh 100 kilos. 4 i didn't never used to have lunch at school. i always had lunch at home. 5 i didn't use to like swimming, but i go quite a lot now. 6 on fridays, we use to watch a dvd at home together. 7 last week, i used to have to study for my exams. 7 last week, i used to have to study for my exams. 8 my grandparents usually come to stay with us at christmas