时起时伏
on-and-off;remain a live issue;now rise,now fall;have ups and downs
围绕铀浓缩计划,国际斗争~。There were on-and-off international disputes over the uranium enrichment plan. or:International disputes over the uranium enrichment plan remained a live issue.
时起时伏shí qǐ shí fú
形容接二连三地起来。now rise, now fall; have up and down