step up to do or doing?please explain it

step up to do or doing?please explain it give up to do sth or give up doing sth? Please explain it to me.翻译. be up to do be up to doing be up to sb to do sth it is up to lead to do or doing it is my frist time to do sth / or doing sth/or do sth? Could you please explain it to me?With p_____. what is the sonnet? please help me to explain it. what a gem!Please explain it to me . let me ___ it,please. A:did B:to do C:doing D:do the first step in doing the first step to do 的区别 turn 加to do or doing?