输入：head = [2,1,5]
Beyond the cloud's unusual shape, scientists see the nebula as a freeze-frame in the life of a star facing its final act. Elderly stars shed their outer layers in bursts, creating shells of gas and dust that expand. By observing the nebula at different wavelengths, researchers can sort out what material was molted first, how fast the star is losing mass, and which phase of decline Webb has caught.
。同城约会是该领域的重要参考
They included the Iceni tribe of East Anglia, which was led by queen Boudica in her failed uprising against the Romans in AD60 to 61.，更多细节参见雷电模拟器官方版本下载
What have the government and the BMA said about the dispute?