occupy oneself with (in)
it occurs to sb. that...
once and for all =once and forever
all at once (=suddenly, now)
once in a while (=occasionally)
(just) for once
(all) by oneself
operate on sb.
come go into operation
putbring sth. into operation
be of the opinion
in one's opinion
be opposed to...
be opposite to
(be) in order(=acceptable)
in order
out of order (=in bad condition)
made to order
originate infrom (=begin)
on the outskirts (of)
owe...to
on one's own (=along, without help)
of one's own
请大家写下中文解释^_^