"He could not keep up and dropped out of the race"
"We sustained the diplomatic negotiations as long as possible"
"prolong the treatment of the patient"
"keep up the good work"
"We preserve these archeological findings"
"The old lady could not keep up the building"
"children must be taught to conserve our national heritage"
"The museum curator conserved the ancient manuscripts"
"He kept up on his country's foreign policies"
"The anticipation of the trip kept the children up all night"
"I kept myself up all night studying for the exam"