, у меня сейчас очень тяжёлая ситуация ребята

1. She (has/had been sitting) at the window since 10 o'clock. (оба варианта применимы, т. к. нет привязки ко времени)
2. He will (be training) from 6 till 8 o'clock next Friday.
3. I didn't speak to him because he (was making) expirement.
4. Now they are ( deciding) where to go for the Holyday this summer.
5. By 5 o'clock the device (had been operating) for 3 hours and didn't stop.
6. I'd like to know what (has) happened to him. (оба варианта применимы) 7. By this time tomorrow the train will (have left) 

My mom asked me to go to the self - service shop and by rice, meat and fruits. I spent 10 min to find meat and fruits and nearly 30 min i looked for a rice. I had no idea where it was. Suddenly i looked through the shop window and saw a shop assistant in the street. he looked strange. he turned his head left and right. it was fishily. after 15 sec i saw a man in black clothes. he gave something to the shop assistant and went away. Then shop assistant came back to the shop and continied to serve the customers and display goods as usual. i was shocked. i was a witness of transfer of drugs! wow! hm.. it was interesting: how much did it cost? and why did he decide to buy it in the middle of work day? maybe it was a sale. ha-ha. drug-sale. why not? Stop. I had to catch him and called  the police. I looked after the assistant and noticed that he threw something in the basket. maybe it was adrug price or number of the diller. I had to have this piece of paper. i tried to be invisible. when he was busy and had a conversation with the customers i picked up the piece of paper and saw... the love confession from the girl which is very modest and asked her brother to give it instead her. i was a lucky guy- i disclosed a fake crime after 10 min. So i took a rice, went to the counter and paid to the cashier money. he gave back the change and i went home. what can i say? it is a good shop. with good shop assistants. I recommend.