1. they have talked/have been talking about it all morning. 2. he's not here because he has been going/has gone to work. he'll be back at 4 o'clock. 3. the children cleaned/have been cleaning the playground yesterday. 4. she has studled/has been studying all day. 5. i worked/have benn working without a break since 8 o'clock 6. i have been walking/walked to the park last week. с объяснением