12 Choose the correct tense. 1 I have been watching / I am watching TV for two hours.
2 My sister has been visiting / is visiting China.
3 Lin has been hiking/ is hiking in the mountain for three days.
4 Lura has been having/ is having dinner at the moment.
5 I have been writing/ am writing a letter.
6 Ben has been skiing/ is skiing since he was five.
urgent!​