本文作者： 21ST

VIP教师会员和本期电子版订户登录后下载

DO you dare to challenge NASA (美国国家宇航局)? Nico Marquardt, a 13-year-old German teenager does. Marquardt thinks that NASA''s figures (数据) for whether the Earth will be hit by a large asteroid in 2036 are wrong. NASA, however, says its figures are right.