to understand, especially after a long time
catch on
to not make as much progress as someone else
fall behind
to stop going to school before finishing the course
drop out of
to give your completed task back to the teacher
hand in
to give something to each person in a group
hand out
to stay on the same level as someone or something
keep up with
to make a choice
opt for
to fail to use an opportunity
miss out on
to join a group or an organization
sign up for
to delay an activity until a later time
put off
to start working or studying hard
knuckle down
to study in a serious and determined way
to hit the books
to make more effort than is expected
to go the extra mile
to make strangers more friendly
to break the ice
to be able to be changed
to not be set in stone
to calm down and be more realistic
to bring it down to Earth
