Hello.I'm Sandy. I did an Ex. yesterday and I didn't know why my answer was wrong. Representatives for the Business Environment Council said authorities should teach the public how energy efficiency saves money.
That can only be done if manufacturers fully test their equipment for efficiency Q4. __________(during/through.over) the long term, BEC said.
The correct answer is 'over' but why? When do we use during,through and over? Thank you.