— Mary, how did your Math test go?
— I had thought I ________, but in fact I came in the top 10 in my class.
A:should have failed
B:couldn't have failed
C:might have failed
D:shouldn't have failed
我国在南极洲建立科学考察站一般都选择在( )
显性基因用____表示,隐性基因____表示。
Mike a blue shirt.
如图,AB∥CD,AD和BC相交于点O,∠A=20°,∠COD=100°,则∠C的度数是( )
I can play ________ chess, so I want to join the chess club.