统计原则、统计调查、统计整理和统计分析是构成统计活动的四个基本环节。( )
参考答案：错
It was on November 15, 2010 ______ a big fire happened in Shanghai, ______ was a great shock to lots of people.[ ]
A. when; that
B. that; when
C. which; when
D. that; which
睑弦赤烂是以____、溃烂、刺痒为临床特征的眼病。
