【计】 central office exchange
centrality; centre; centricity; core; heart; hub; kernel
【医】 center; centra; centre; centro-; centrum; core
bureau; game; chessboad; limit; office; station
【经】 bureau
exchange; interchange; change for; commute; permutation; reciprocation
replacement
【计】 exchange; swap; swapping; switching; transput; X
【医】 chiasmapy; cross-over; crossing-over
【经】 interchange; swap
chance; crucial point; engine; machine; occasion; organic; pivot; plane
flexible
【医】 machine