Scientists are convinced the positive effect of laughter physical and mental health.
Everything,unless otherwise ________,will go on as planned.
—It's a pity that Andrew didn't want to go to the conference. —________ willing to go,we could have paid all his expenses.
—Why do you look so puzzled? —Oh,I ________ over a most difficult maths problem.
—Peter!Let's hurry.The boss is coming. —Oh,I was afraid that we ________ her.
The past two years ________ a sharp rise in oil price,which adds to the burden of auto transportation industry.