1．There is no sense upsetting (upset) yourself about it now.Look forward and everything will be all right.
2．In addition，using mobile phones will add to their parents' economic burdens.
3．He asked several questions concerning (concern) the future of the company.
4. —How did you pass the challenging test?
—It was a long time before I found a series of suitable methods.
5．Human beings and animals should get along/on well with each other.
6．While travelling (travel) in Europe，he found many interesting things and experienced different cultures.
7．Since you have questions，why not turn to him for some tips (tip)?
8．The old man went through many difficulties and suffered (suffer) a lot from them.
9．Dave went through his pockets looking for the keys.
10．With a lot of difficult problems to settle (settle)，the newlyelected president is having a hard time.
