第1个回答 2011-03-18
sometimes; occasionally; at times; at whiles; now and then; now and again; once in a while; on occasion; in some cases; every so often
第2个回答 2011-03-18
sometimes
at times
now and then本回答被提问者采纳
第3个回答 2011-03-18
from time to time
第4个回答 2011-03-23
sometimes
at times
from time to time
now and then
every now and every then