1 - a) She didn't buy the vase because she didn't have enough money
2 - d) It was very cold, so Joe put his coat on
3 - b) I was in the bathroom when the doorbell rang
4 - f) I washed the dishes and I watched TV
5 - c) I shut the window, then I closed the curtains
6 - e) He screamed for help, but nobody could hear him