“紫荆绽后白莲开,喜事蹁跹拦路来。神州大地齐欢庆,一国两制添新彩。”诗中的“白莲开”是指( )
A:开国大典
B:北京申奥成功
C:香港回归
D:澳门回归
四边形ABCD的对角线相交于点O,且AO=BO=CO=DO,则这个四边形( )
We had to rely on our own intelligence to create ________and balance with the environment during development.