John last had his hair cut 6 months ago -> John hasn't...

(a)  

She last wrote a poem 10 years ago. -> She hasn't (a)  

Our group last went for a picnic 1 year ago. -> Our group hasn't (a)  

1. If your father doesn’t stop hitting your mother, I will report him to the police.   -> Unless (a)  

If the house is not expensive, I will buy it. -> Unless...

(a)  

If students don’t stick to the school rules, they will be punished.-> Unless...

(a)  

If it doesn’t rain, there will be no water for crop.-> Unless...

(a)  

The seminar was not held on my day off. I couldn’t join in it. -> If (a)  

It rained heavily. The outdoor party was cancelled. -> If...

(a)  

He supported her finance. She could conduct the survey. -> If...

(a)  

It was thanks to the LG sponsor. The football tournament was successful. -> If...

(a)