At first it was but like a swallow , then a lark , then an eagle , then as vast as a spring cloud , and then it filled the starry heavens .
起先，它只像燕子一般大小，而后像云雀，像兀鹰，像春天的云团，最后，竟至遮蔽了星光闪耀的天空。
Analyses of Microphysical Features for Spring Precipitation Cloud Layers in East of Qinghai
高原东部春季降水云层的微物理特征分析
spring cloudspring cloudspring cloud