单项选择题
A．on B．to C．with D．at
A．they would not have to make any other payment later B．they would not be guaranteed against further payment C．the plan would cover further tuition increases D．the plan would be replaced by a guaranteed investment contract
A．simplifying the entire process of detection B．the mechanic design of thermal cameras C．substituting new approaches for polygraph D．the discovery that one blushes while telling lies