A:有颜色的变化
B:有新物质生成
C:有沉淀生成
D:有发光发热现象
如图所示,在△ABC中,∠C=90°,DE⊥AB于D,BC=BD,结果AC=3cm,那么AE+DE=( )
下图为某城区1月某日24小时内不同时刻海平面气压分布示意图,四幅图的等压距均为2.5百帕。读图完成下列问题.
My Travel Plan
⒈On Saturday I will get ready for the trip.
⒉On Monday I will go to Beijing.
⒊On Tuesday I will go to the Palace Museum.
⒋On Wednesday I will go to Beihai Park.
⒌On Thursday I will go to Wangfujing Street.
⒍On Friday I will go home.
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