A:①②
B:①③
C:②③
D:①②④
算一算
Immediately upon seeing his manner, I knew he had a ____ (内疚的) conscience.
下列叙述中,错误的是( )
根据如图“南极地区略图”,完成问题.
我国四个南极科学考察站中,无极昼极夜现象的是( )