Our teacher's advice is very -(very usefuland helpful) to us

Our teacher's advice is very _(very usefuland helpful) to us students.
——When will you go for a trip in the coming holiday?I haven't decided yet.
——_(maybe) I'll go to a city by the sea.
Helen has the _ to face and correct her mistakes.
每个人偶尔都会有些问题Everyone has some problems ____________.