HannahLin的ScalersTalk第四轮新概念朗读持续力训练Day 61 20181207
Lesson61TroublewiththeHubble哈勃望远镜的困境TheHubbletelescopewaslaunchedintospacebyNASAonApril20,1990atacostofoverabilliondollars.RightfromthestarttherewastroublewiththeHubble.Thepicturesitsentuswereverydisa