keep to ...

phr

• ① 严守(时间、规则等);不离开(家、正轨);不离(本题等)
  • He keeps to his promise.他遵守诺言。
  • You must keep to the deadlines [speed limit].你必须严守期限[速度限制]。
  • Keep to the right.[告示]靠右通行。