[填空题]
The Eiffel Tower (Fig. 13–29) is built oxh)294di28ty pq;f1h l pwra1g4hd m* nq(xxyf wrou7 cix+5jl io yb;b8k4jght iron approximately 300 m tall. Estimate how much its jbxc;4j5b l8 yii7ko+height changes between July (average temperature of 25°C) and January (average temperature of 2 $^{\circ} $ C). Ignore the angles of the iron beams, and treat the tower as a vertical beam. m