1．Hard as/though they tried, they couldn't make her change her mind.
2．(2019·安徽六校联考)This company was accused of using misleading advertisements in its promotion of the weight loss pills.
3．To work out the difficult maths problem，I have consulted(consult) Professor Russell several times.
4．—Shall we go for a drink at one o'clock this afternoon?
—Sorry，I can't make it.Will two o'clock be OK?
5．They set out to solve (solve) the pollution problems as soon as they got to the place.
6．I was walking along the river when I heard a boy crying for help.
7．At last，the boy acknowledged stealing/having stolen (steal) the money from his mother's pocket.
