片语
at intervals时时,不时;相隔一定距离(或时间)
frequentlyand from time to time往往
update from time to time桌面月历壁纸
from m time to time有时
From time to time to时时地
for time to time有时
alarm from time to time定时报警
appear from time to time从表面看来
time from time to time时常
continue from time to time断断续续