[单选题]
A polar bear starts at the North Pole.kxk:rt fsph0li08jt15 4c8 n t It travels 1.0 km soujuq:s0s 5rjt2 2 lxpd(th, then 1.0 km east, then 1.0 km north, then 1.0 km west to return to its starting point. This trip takes 45 min. What was the bear's averages: xut(pq 0 rj25ljds2 speed?
