at once;
immediately;
at length;
in the mean time;
meanwhile;
at the same time;
in the end; then; soon;
not long after;
later; at once;
at last; finally;
some time ago;
at present;
all of a sudden;
from this time on;
from time to time;
since then; when;
whenever;
next point;
a few minutes later;
formerly;
as; once;
since;
occasionally;
in a moment;
shortly;
whereupon;
previously