keep up -
maintain a required pace or level; "He could not keep up and dropped out of the race"
keep pace,
keep step maintain the same pace; "The child cannot keep step with his big brother"
keep up -
prevent from going to bed at night; "The anticipation of the trip kept the children up all night"; "I kept myself up all night studying for the exam"
stay up,
sit up not go to bed; "Don't stay up so late--you have to go to work tomorrow"; "We sat up all night to watch the election"
keep up -
keep informed; "He kept up on his country's foreign policies"
trace,
follow follow, discover, or ascertain the course of development of something; "We must follow closely the economic development is Cuba" ; "trace the student's progress"
