Write questions for these answers with How long and the present perfect. 1. Theyve been in class for 15 minutes. ............. 2. Hes known John since he was at primary school. ............. 3. Mary has worked in Miami since for one year. ............... 5. My mother has had a motorbike since last year. .............. 6. Theyve studied Chinse for two years. ..........

1. How long have they been in class?
2. How long has he known John?
3. How long has Mary worked in Miami?
5. How long has your mother had a motorbike?
6. How long have they studied Chinese?